Discussion:
Ignition question involving use of ballast resistor
(too old to reply)
Jack
2008-12-31 02:56:14 UTC
Permalink
1987 Dodge Dakota 3.9L carbed

I recently posted on rec.autos.tech about the problems I was having with
an MSD 5900 Blaster ignition and an MSD 8202 Baster 2 coil. It seems I
could use one or the other with no problem, either the MSD ignition with
the stock coil or the MSD coil with the stock ignition, but if I had
both installed I would get a stumble on accelerating from a dead stop.

From this behavior I deduced that, for some reason, the problem was
being caused by too much ignition voltage. To test out that theory I
installed a 1 ohm ballast resistor in line with the +12 volts going to
the coil. Voila, the problem vanished and I was back to strong, smooth
acceleration from a dead stop. So then I tried a 1/2 ohm ballast
resistor and the stumble returned, but not as bad, so I went back to the
1 ohm resistor.

The stock coil has about a 1.5 ohm primary and the MSD coil has a .7 ohm
or so primary. I don't know what impact this has on the situation but
it's info that I have and I figured I might as well throw it in if I am
going to all the trouble of posting this and you are going to all the
trouble of reading it.

Now we get to meat of the my puzzlement. The ignition wires that I have
on the engine measure about 3000 ohms per foot. For about $45 I can buy
some MSD Street Fire wires that are only 500 ohms per foot. I know a bit
about electricity, but not enough to know whether or not these wires
would enable me to run the MSD ignition and coil without the ballast
resistor. After all, the point of an MSD ignition upgrade is to get
longer stronger spark to the plug.

I don't have a clue as to why the engine stumbles with both the MSD
ignition and coil installed. From the symptoms it seems to me that it
must be because of too much voltage at the coil tower, but why that
might be causing the problem is beyond me.

Could it be because the high voltage is leaking out to ground somewhere
on the way to the plugs? I checked the engine at idle in a dark area at
night and saw no evidence of arcing. Could the high resistance wires be
the cause? If so, what is the rationale? I can't think of one.

Well that's it. At present, I am more than happy with the ballast
resistors. The truck runs great. Just curious as hell as to what might
be going on.

Jack
t***@yahoo.com
2008-12-31 04:40:03 UTC
Permalink
ROTFLMAO !!!
Steve Lusardi
2008-12-31 09:09:09 UTC
Permalink
Jack,
The purpose of a ballast resister is to allow a lower voltage ignition coil
to be used. The reason for this is that when the starter motor is engaged,
battery voltage will drop to say 8 V. You will note that when wired
correctly the ballast resister is bypassed at that time allowing the coil to
create adequate spark during lower battery voltage conditions . When the
starter is then disengaged the resister bypass is also dropped and the
resister is now in play to reduce excessive heating of the coil. Electronic
ignitions are very sensitive to coil configurations, as they provide coil
drive and can be permanently damaged if the DC resistance of the coil is too
low. Follow the manufacturer's recommendations.
Steve
Post by Jack
1987 Dodge Dakota 3.9L carbed
I recently posted on rec.autos.tech about the problems I was having with
an MSD 5900 Blaster ignition and an MSD 8202 Baster 2 coil. It seems I
could use one or the other with no problem, either the MSD ignition with
the stock coil or the MSD coil with the stock ignition, but if I had
both installed I would get a stumble on accelerating from a dead stop.
From this behavior I deduced that, for some reason, the problem was
being caused by too much ignition voltage. To test out that theory I
installed a 1 ohm ballast resistor in line with the +12 volts going to
the coil. Voila, the problem vanished and I was back to strong, smooth
acceleration from a dead stop. So then I tried a 1/2 ohm ballast
resistor and the stumble returned, but not as bad, so I went back to the
1 ohm resistor.
The stock coil has about a 1.5 ohm primary and the MSD coil has a .7 ohm
or so primary. I don't know what impact this has on the situation but
it's info that I have and I figured I might as well throw it in if I am
going to all the trouble of posting this and you are going to all the
trouble of reading it.
Now we get to meat of the my puzzlement. The ignition wires that I have
on the engine measure about 3000 ohms per foot. For about $45 I can buy
some MSD Street Fire wires that are only 500 ohms per foot. I know a bit
about electricity, but not enough to know whether or not these wires
would enable me to run the MSD ignition and coil without the ballast
resistor. After all, the point of an MSD ignition upgrade is to get
longer stronger spark to the plug.
I don't have a clue as to why the engine stumbles with both the MSD
ignition and coil installed. From the symptoms it seems to me that it
must be because of too much voltage at the coil tower, but why that
might be causing the problem is beyond me.
Could it be because the high voltage is leaking out to ground somewhere
on the way to the plugs? I checked the engine at idle in a dark area at
night and saw no evidence of arcing. Could the high resistance wires be
the cause? If so, what is the rationale? I can't think of one.
Well that's it. At present, I am more than happy with the ballast
resistors. The truck runs great. Just curious as hell as to what might
be going on.
Jack
Jack
2008-12-31 20:36:16 UTC
Permalink
Post by Steve Lusardi
Jack,
The purpose of a ballast resister is to allow a lower voltage ignition coil
to be used. The reason for this is that when the starter motor is engaged,
battery voltage will drop to say 8 V. You will note that when wired
correctly the ballast resister is bypassed at that time allowing the coil to
create adequate spark during lower battery voltage conditions . When the
starter is then disengaged the resister bypass is also dropped and the
resister is now in play to reduce excessive heating of the coil. Electronic
ignitions are very sensitive to coil configurations, as they provide coil
drive and can be permanently damaged if the DC resistance of the coil is too
low. Follow the manufacturer's recommendations.
Steve
Steve, thanks for the heads up on the wiring. I didn't run the B+ wire
to the coil from the starter relay because I felt that the MSD ignition
and MSD coil together would provide enough spark going through the
ballast resistor even with the engine cranking. It proved to be true.
The engine starts up immediately with the 12+ volts from the ignition
switch going to the coil through the ballast resistor. I was mainly
intent at the time to test the idea that the stumble problem was being
caused by trying to push too high a voltage to the plug gap. The ballast
resistor was my way of reducing the voltage at the plug gap while using
both the MSD coil and ignition together.

The ballast resistor is rated at 1 ohm and measures 1 ohm. The Blaster
coil primary is rated at .7 ohms and measures .6 ohms. The resistance of
the coil primary of the MSD Blaster coil and the added ballast resistor
measures 1.6 ohms, all measured on a digital meter. The recommended
primary resistance for the coil on this vehicle is 1.34 to 1.55 ohms.

I don't know what stress is being placed on the spark control computer
when using the MSD Blaster coil with the stock ignition and no ballast
resistor, but the engine runs great under this configuration, with very
smooth acceleration a dead stop. The same is true when using the MSD
ignition box with the stock coil. The problem of a stumble on
accelerating from a dead stop happens only when both are used together.

With the addition of the ballast resistor the computer now sees what it
was designed to see at the primary winding, so there should be no
problem of the kind you are warning me about, having too low resistance
at the primary.

As to what is causing the stumble on accelerating from a dead stop using
the MSD ignition and coil and no ballast, I am still in the dark. After
all, the engines performs great with just the coil and no ballast.

Jack
Post by Steve Lusardi
Post by Jack
1987 Dodge Dakota 3.9L carbed
I recently posted on rec.autos.tech about the problems I was having with
an MSD 5900 Blaster ignition and an MSD 8202 Baster 2 coil. It seems I
could use one or the other with no problem, either the MSD ignition with
the stock coil or the MSD coil with the stock ignition, but if I had
both installed I would get a stumble on accelerating from a dead stop.
From this behavior I deduced that, for some reason, the problem was
being caused by too much ignition voltage. To test out that theory I
installed a 1 ohm ballast resistor in line with the +12 volts going to
the coil. Voila, the problem vanished and I was back to strong, smooth
acceleration from a dead stop. So then I tried a 1/2 ohm ballast
resistor and the stumble returned, but not as bad, so I went back to the
1 ohm resistor.
The stock coil has about a 1.5 ohm primary and the MSD coil has a .7 ohm
or so primary. I don't know what impact this has on the situation but
it's info that I have and I figured I might as well throw it in if I am
going to all the trouble of posting this and you are going to all the
trouble of reading it.
Now we get to meat of the my puzzlement. The ignition wires that I have
on the engine measure about 3000 ohms per foot. For about $45 I can buy
some MSD Street Fire wires that are only 500 ohms per foot. I know a bit
about electricity, but not enough to know whether or not these wires
would enable me to run the MSD ignition and coil without the ballast
resistor. After all, the point of an MSD ignition upgrade is to get
longer stronger spark to the plug.
I don't have a clue as to why the engine stumbles with both the MSD
ignition and coil installed. From the symptoms it seems to me that it
must be because of too much voltage at the coil tower, but why that
might be causing the problem is beyond me.
Could it be because the high voltage is leaking out to ground somewhere
on the way to the plugs? I checked the engine at idle in a dark area at
night and saw no evidence of arcing. Could the high resistance wires be
the cause? If so, what is the rationale? I can't think of one.
Well that's it. At present, I am more than happy with the ballast
resistors. The truck runs great. Just curious as hell as to what might
be going on.
Jack
jim <"sjedgingN0sp"@
2008-12-31 12:41:20 UTC
Permalink
Post by Jack
1987 Dodge Dakota 3.9L carbed
I recently posted on rec.autos.tech about the problems I was having with
an MSD 5900 Blaster ignition and an MSD 8202 Baster 2 coil. It seems I
could use one or the other with no problem, either the MSD ignition with
the stock coil or the MSD coil with the stock ignition, but if I had
both installed I would get a stumble on accelerating from a dead stop.
From this behavior I deduced that, for some reason, the problem was
being caused by too much ignition voltage. To test out that theory I
installed a 1 ohm ballast resistor in line with the +12 volts going to
the coil. Voila, the problem vanished and I was back to strong, smooth
acceleration from a dead stop. So then I tried a 1/2 ohm ballast
resistor and the stumble returned, but not as bad, so I went back to the
1 ohm resistor.
Normally when all is working as it should, what limits voltage is the spark
plug gap and the engine compression (actually the absolute pressure inside
the cylinder). A wider gap or more pressure will cause the voltage to climb
higher before it will cross the gap. acceleration from a stop often will
produce the greatest pressure inside the cylinder.
Post by Jack
Could it be because the high voltage is leaking out to ground somewhere
on the way to the plugs?
Yes it could be that - If the voltage climbs too high too fast it finds
another path instead of the spark plug gap. Ultimately, your ballast
resister doesn't limit the voltage at the spark plug but it does slow down
the rise in voltage which means that some other points in the secondary
won't get quite as high. If stray arcing in the secondary is what is
happening it would be likely that it would get progressively worse over time
as the stray arcs develops a carbon trail that the current can follow more
easily.

The cause could also be in the primary there may be something that
saturates in the primary or even something intended to limit voltage/current
to protect against damage.

-jim
Post by Jack
I checked the engine at idle in a dark area at
night and saw no evidence of arcing. Could the high resistance wires be
the cause? If so, what is the rationale? I can't think of one.
Well that's it. At present, I am more than happy with the ballast
resistors. The truck runs great. Just curious as hell as to what might
be going on.
Jack
HLS
2008-12-31 14:25:38 UTC
Permalink
Post by jim <"sjedgingN0sp"@
Normally when all is working as it should, what limits voltage is the spark
plug gap and the engine compression (actually the absolute pressure inside
the cylinder). A wider gap or more pressure will cause the voltage to climb
higher before it will cross the gap. acceleration from a stop often will
produce the greatest pressure inside the cylinder.
This was especially true when the Kettering system was used. When
capacitive
discharged systems came along, it pretty much stopped being true. Their
rise times are so short and transformer action so definite that they usually
put
up much more constant ignition performance.

I dont know what the multiple spark discharge systems do. Are they CD, or
something else?

Some early studies showed that, all things being equal, a small single spark
ignited the fuel as well as anything else. Some university studies in
England
showed that high performance ignition systems which gave significant gains
were possible, but they were not necessarily simple and cheap either.

It is my opinion, and nothing more, that there is little to be gained from
systems
like the MSD for normal driving. For racing, maybe....
jim <".sjedgingN0sp"@
2008-12-31 14:44:07 UTC
Permalink
Post by HLS
Post by jim <"sjedgingN0sp"@
Normally when all is working as it should, what limits voltage is the spark
plug gap and the engine compression (actually the absolute pressure inside
the cylinder). A wider gap or more pressure will cause the voltage to climb
higher before it will cross the gap. acceleration from a stop often will
produce the greatest pressure inside the cylinder.
This was especially true when the Kettering system was used. When
capacitive
discharged systems came along, it pretty much stopped being true.
What stopped being true? The statement you are responding to has never stopped
being true. It may have become unimportant to know that it is true, but that is
hardly the same as being not true..
Post by HLS
Their
rise times are so short and transformer action so definite that they usually
put
up much more constant ignition performance.
How does this information relate to solving the OP's problem? The rate at which
voltage is developed in the coil is going to be a function of resistance and
inductance no matter what. Which is why changing resistance produces different
results.
Post by HLS
I dont know what the multiple spark discharge systems do. Are they CD, or
something else?
Some early studies showed that, all things being equal, a small single spark
ignited the fuel as well as anything else. Some university studies in
England
showed that high performance ignition systems which gave significant gains
were possible, but they were not necessarily simple and cheap either.
It is my opinion, and nothing more, that there is little to be gained from
systems
like the MSD for normal driving. For racing, maybe....
His intent is related to neither of those - it is to improve emissions.

-jim
d***@my-deja.com
2008-12-31 16:24:14 UTC
Permalink
Post by HLS
I dont know what the multiple spark discharge systems do. Are they CD, or
something else?
They're usually ordinary flyback systems, just like points systems. I
never saw a CD multistrike system, but that was long ago, when every
CD system was triggered by an SCR, a device that can be turned on but
not turned off. But since then, high voltage, high current devices
that can be turned off have become more common, so multistrike CD
should be easier to implement. I had a double-strike CD system that
consisted of 2 separate CD units because I didn't know how to make
anything better.
Post by HLS
It is my opinion, and nothing more, that there is little to be gained from
systems like the MSD for normal driving. For racing, maybe....
True, thanks to the EPA and its stringent emissions standards that
include cold weather, cold engine conditions.
Jack
2008-12-31 21:05:20 UTC
Permalink
Post by HLS
Post by jim <"sjedgingN0sp"@
Normally when all is working as it should, what limits voltage is the spark
plug gap and the engine compression (actually the absolute pressure inside
the cylinder). A wider gap or more pressure will cause the voltage to climb
higher before it will cross the gap. acceleration from a stop often will
produce the greatest pressure inside the cylinder.
This was especially true when the Kettering system was used. When
capacitive
discharged systems came along, it pretty much stopped being true. Their
rise times are so short and transformer action so definite that they usually
put
up much more constant ignition performance.
I dont know what the multiple spark discharge systems do. Are they CD, or
something else?]
HLS, the unit that I have is the MSD 5900 Blaster. It is not multiple
spark, but one strong spark through 20° degrees of rotation and it is
induction discharge, not capacitive. But most, if not all, of MSD's
other ignition units, with the exception of the MSD 5, are capacitive
discharge.
Post by HLS
Some early studies showed that, all things being equal, a small single spark
ignited the fuel as well as anything else. Some university studies in
England
showed that high performance ignition systems which gave significant gains
were possible, but they were not necessarily simple and cheap either.
It is my opinion, and nothing more, that there is little to be gained from
systems
like the MSD for normal driving. For racing, maybe....
I installed the MSD components in the hope that they would help pass
California smog requirements. I had to swap out the original feedback
carb for a non-feedback version because the mixture control solenoid in
the feedback carb is no longer being provided by anyone as a replacement
part and owners of vehicles with this carbs are left to fend for
themselves. I had the non-feedback carb installed the last time I had
the truck smogged and it passed, but only just. I was 2 ppm below the
max for HCs.
Jack
2008-12-31 20:54:48 UTC
Permalink
Post by jim <"sjedgingN0sp"@
Post by Jack
1987 Dodge Dakota 3.9L carbed
I recently posted on rec.autos.tech about the problems I was having with
an MSD 5900 Blaster ignition and an MSD 8202 Baster 2 coil. It seems I
could use one or the other with no problem, either the MSD ignition with
the stock coil or the MSD coil with the stock ignition, but if I had
both installed I would get a stumble on accelerating from a dead stop.
From this behavior I deduced that, for some reason, the problem was
being caused by too much ignition voltage. To test out that theory I
installed a 1 ohm ballast resistor in line with the +12 volts going to
the coil. Voila, the problem vanished and I was back to strong, smooth
acceleration from a dead stop. So then I tried a 1/2 ohm ballast
resistor and the stumble returned, but not as bad, so I went back to the
1 ohm resistor.
Normally when all is working as it should, what limits voltage is the spark
plug gap and the engine compression (actually the absolute pressure inside
the cylinder). A wider gap or more pressure will cause the voltage to climb
higher before it will cross the gap. acceleration from a stop often will
produce the greatest pressure inside the cylinder.
Post by Jack
Could it be because the high voltage is leaking out to ground somewhere
on the way to the plugs?
Yes it could be that - If the voltage climbs too high too fast it finds
another path instead of the spark plug gap. Ultimately, your ballast
resister doesn't limit the voltage at the spark plug but it does slow down
the rise in voltage which means that some other points in the secondary
won't get quite as high. If stray arcing in the secondary is what is
happening it would be likely that it would get progressively worse over time
as the stray arcs develops a carbon trail that the current can follow more
easily.
The cause could also be in the primary there may be something that
saturates in the primary or even something intended to limit voltage/current
to protect against damage.
-jim
Thanks, jim, for the feedback. I ran the engine at idle in the dark and
could see no evidence of arcing. Of course this is different from
accelerating the engine under a load from idle.

At any rate, if the problem is caused by current leak, do you think that
changing the plug wires from 3000 ohms per foot to 500 ohms per foot
would help? It would only cost me about $50 or less to find out, but I
hate throwing money at a problem to see what sticks.

Jack
Post by jim <"sjedgingN0sp"@
Post by Jack
I checked the engine at idle in a dark area at
night and saw no evidence of arcing. Could the high resistance wires be
the cause? If so, what is the rationale? I can't think of one.
Well that's it. At present, I am more than happy with the ballast
resistors. The truck runs great. Just curious as hell as to what might
be going on.
Jack
jim <"sjedgingN0sp"@
2008-12-31 22:31:17 UTC
Permalink
Post by Jack
I checked the engine at idle in a dark area at
night and saw no evidence of arcing. Could the high resistance wires be
the cause? If so, what is the rationale? I can't think of one.
My guess is the cause is in the primary not the secondary. But if it was due
to a leak in the secondary you would probably have to be looking at it in
the dark while it was happening.
Changing the spark plug wire resistance shouldn't have any effect. Current
doesn't really flow thru the wires until the spark plug starts to arc. The
tail end of the wave form will be affected but not the initial spike.
Getting rid of the resistance won't change the peak voltage in a measurable
way.

It is not clear how this is going to help with your emissions. If the
mixture ia a bit rich all the spark in the world is going to get the extra
fuel to burn. If it is a tad lean it might help, but it doesn't sound like
that is the case.

-jim
Post by Jack
Well that's it. At present, I am more than happy with the ballast
resistors. The truck runs great. Just curious as hell as to what might
be going on.
Jack
Jack
2009-01-01 00:30:31 UTC
Permalink
Post by jim <"sjedgingN0sp"@
Post by Jack
I checked the engine at idle in a dark area at
night and saw no evidence of arcing. Could the high resistance wires be
the cause? If so, what is the rationale? I can't think of one.
My guess is the cause is in the primary not the secondary. But if it was due
to a leak in the secondary you would probably have to be looking at it in
the dark while it was happening.
Changing the spark plug wire resistance shouldn't have any effect. Current
doesn't really flow thru the wires until the spark plug starts to arc. The
tail end of the wave form will be affected but not the initial spike.
Getting rid of the resistance won't change the peak voltage in a measurable
way.
It is not clear how this is going to help with your emissions. If the
mixture ia a bit rich all the spark in the world is going to get the extra
fuel to burn. If it is a tad lean it might help, but it doesn't sound like
that is the case.
-jim
I will find out soon what the emissions are. I just got back from a
freeway run and some stop and go driving and the only problem was a sag
when I floored it at about 25 to 35 mph, like the accelerator pump was
out of adjustment or the power valve was not opening. I tweaked the pump
linkage a bit but it wasn't out that much. I checked timing and it is at
spec. Checking the power valve will involve tearing into the carb, which
I will save for another day. It could be that the main jets are a tad
too small, but before I do anything else I will take it to a smog shop
for a dry run to see what the emissions are. At least the ignition
system seems to be performing okay and that was my main worry.
Scott Dorsey
2008-12-31 14:26:24 UTC
Permalink
Post by Jack
From this behavior I deduced that, for some reason, the problem was
being caused by too much ignition voltage. To test out that theory I
installed a 1 ohm ballast resistor in line with the +12 volts going to
the coil. Voila, the problem vanished and I was back to strong, smooth
acceleration from a dead stop. So then I tried a 1/2 ohm ballast
resistor and the stumble returned, but not as bad, so I went back to the
1 ohm resistor.
The ballast resistor does more than just change the voltage, it can change
the shape of the pulse through the coil as well.
Post by Jack
Now we get to meat of the my puzzlement. The ignition wires that I have
on the engine measure about 3000 ohms per foot. For about $45 I can buy
some MSD Street Fire wires that are only 500 ohms per foot. I know a bit
about electricity, but not enough to know whether or not these wires
would enable me to run the MSD ignition and coil without the ballast
resistor. After all, the point of an MSD ignition upgrade is to get
longer stronger spark to the plug.
No, using a wire with a lower resistance will _slightly_ increase the
voltage to the plug. But honestly, the difference is very small because
the voltage is so high and current so low that it takes a lot of resistance
to cause much drop.
Post by Jack
I don't have a clue as to why the engine stumbles with both the MSD
ignition and coil installed. From the symptoms it seems to me that it
must be because of too much voltage at the coil tower, but why that
might be causing the problem is beyond me.
What you want is an ignition system analyzer that will let you look at the
signal coming out of the coil on a CRT. This will tell you what is really
happening when you put the ballast resistor in. Ask older shops around town
if they still have an analyzer kicking around.
Post by Jack
Well that's it. At present, I am more than happy with the ballast
resistors. The truck runs great. Just curious as hell as to what might
be going on.
The scope will tell you, and without the scope you have no real chance of
seeing what is happening.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Jack
2008-12-31 21:26:11 UTC
Permalink
Post by Scott Dorsey
Post by Jack
From this behavior I deduced that, for some reason, the problem was
being caused by too much ignition voltage. To test out that theory I
installed a 1 ohm ballast resistor in line with the +12 volts going to
the coil. Voila, the problem vanished and I was back to strong, smooth
acceleration from a dead stop. So then I tried a 1/2 ohm ballast
resistor and the stumble returned, but not as bad, so I went back to the
1 ohm resistor.
The ballast resistor does more than just change the voltage, it can change
the shape of the pulse through the coil as well.
What role does the resistor play when voltage is cut off to the primary?
This is what causes the secondary to produce its voltage, right, the
sudden collapse of the primary field?

Does the inductance produced by the expanding field of the primary limit
the rate of expansionof the field? Is this why there is not a high
voltage produced in the secondary when voltage is applied to the primary?

Could it be that the lower resistance of the MSD coil primary over the
stock coil, .6 to .7 ohms, compared to 1.3 to 1.5 ohms, coupled with the
greatly increased voltage to the primary from the MSD ignition could
cause the field in the primary to expand too quickly and cause a weak
spark at the plug at the wrong time?
Post by Scott Dorsey
Post by Jack
Now we get to meat of the my puzzlement. The ignition wires that I have
on the engine measure about 3000 ohms per foot. For about $45 I can buy
some MSD Street Fire wires that are only 500 ohms per foot. I know a bit
about electricity, but not enough to know whether or not these wires
would enable me to run the MSD ignition and coil without the ballast
resistor. After all, the point of an MSD ignition upgrade is to get
longer stronger spark to the plug.
No, using a wire with a lower resistance will _slightly_ increase the
voltage to the plug. But honestly, the difference is very small because
the voltage is so high and current so low that it takes a lot of resistance
to cause much drop.
Scott, this was what I suspected. It seemed to me that the higher the
voltage, the less impact high resistance wires would have. My thought
was that perhaps the higher resistance wires was causing current to leak
out somewhere besides the plug gap.
Post by Scott Dorsey
Post by Jack
I don't have a clue as to why the engine stumbles with both the MSD
ignition and coil installed. From the symptoms it seems to me that it
must be because of too much voltage at the coil tower, but why that
might be causing the problem is beyond me.
What you want is an ignition system analyzer that will let you look at the
signal coming out of the coil on a CRT. This will tell you what is really
happening when you put the ballast resistor in. Ask older shops around town
if they still have an analyzer kicking around.
Post by Jack
Well that's it. At present, I am more than happy with the ballast
resistors. The truck runs great. Just curious as hell as to what might
be going on.
The scope will tell you, and without the scope you have no real chance of
seeing what is happening.
--scott
Thanks, scott. I really appreciate your input.

Jack
Steve Austin
2009-01-01 18:27:05 UTC
Permalink
Post by Scott Dorsey
Post by Jack
From this behavior I deduced that, for some reason, the problem was
being caused by too much ignition voltage. To test out that theory I
installed a 1 ohm ballast resistor in line with the +12 volts going to
the coil. Voila, the problem vanished and I was back to strong, smooth
acceleration from a dead stop. So then I tried a 1/2 ohm ballast
resistor and the stumble returned, but not as bad, so I went back to the
1 ohm resistor.
The ballast resistor does more than just change the voltage, it can change
the shape of the pulse through the coil as well.
Post by Jack
Now we get to meat of the my puzzlement. The ignition wires that I have
on the engine measure about 3000 ohms per foot. For about $45 I can buy
some MSD Street Fire wires that are only 500 ohms per foot. I know a bit
about electricity, but not enough to know whether or not these wires
would enable me to run the MSD ignition and coil without the ballast
resistor. After all, the point of an MSD ignition upgrade is to get
longer stronger spark to the plug.
No, using a wire with a lower resistance will _slightly_ increase the
voltage to the plug. But honestly, the difference is very small because
the voltage is so high and current so low that it takes a lot of resistance
to cause much drop.
Post by Jack
I don't have a clue as to why the engine stumbles with both the MSD
ignition and coil installed. From the symptoms it seems to me that it
must be because of too much voltage at the coil tower, but why that
might be causing the problem is beyond me.
What you want is an ignition system analyzer that will let you look at the
signal coming out of the coil on a CRT. This will tell you what is really
happening when you put the ballast resistor in. Ask older shops around town
if they still have an analyzer kicking around.
Post by Jack
Well that's it. At present, I am more than happy with the ballast
resistors. The truck runs great. Just curious as hell as to what might
be going on.
The scope will tell you, and without the scope you have no real chance of
seeing what is happening.
--scott
The modern equipment would be the Snap On Modis or the Snap On Vantage Pro.
Steve
2009-01-06 22:37:52 UTC
Permalink
Post by Scott Dorsey
Post by Jack
From this behavior I deduced that, for some reason, the problem was
being caused by too much ignition voltage. To test out that theory I
installed a 1 ohm ballast resistor in line with the +12 volts going to
the coil. Voila, the problem vanished and I was back to strong, smooth
acceleration from a dead stop. So then I tried a 1/2 ohm ballast
resistor and the stumble returned, but not as bad, so I went back to the
1 ohm resistor.
The ballast resistor does more than just change the voltage, it can change
the shape of the pulse through the coil as well.
And suppresses "ringing" in the circuit.


And given the fact that the electronics that drive the coil are
basically analog amplifiers, it changes their output current profile
directly too.
d***@my-deja.com
2008-12-31 16:15:14 UTC
Permalink
Post by Jack
1987 Dodge Dakota 3.9L carbed
I recently posted on rec.autos.tech about the problems I was having with
an MSD 5900 Blaster ignition and an MSD 8202 Baster 2 coil. It seems I
could use one or the other with no problem, either the MSD ignition with
the stock coil or the MSD coil with the stock ignition, but if I had
both installed I would get a stumble on accelerating from a dead stop.
From this behavior I deduced that, for some reason, the problem was
being caused by too much ignition voltage. To test out that theory I
installed a 1 ohm ballast resistor in line with the +12 volts going to
the coil. Voila, the problem vanished and I was back to strong, smooth
acceleration from a dead stop. So then I tried a 1/2 ohm ballast
resistor and the stumble returned, but not as bad, so I went back to the
1 ohm resistor.
The stock coil has about a 1.5 ohm primary and the MSD coil has a .7 ohm
or so primary. I don't know what impact this has on the situation but
it's info that I have and I figured I might as well throw it in if I am
going to all the trouble of posting this and you are going to all the
trouble of reading it.
I'm going to say MSD designed the output section of their ignition
system wrong, and maybe when the resistance is low, it goes into
current-limiting mode to protect itself. Another possibility is the
high voltage protection for the output section (typically some zener
diodes and capacitor) is interacting badly with the coil primary.
Post by Jack
Now we get to meat of the my puzzlement. The ignition wires that I have
on the engine measure about 3000 ohms per foot. For about $45 I can buy
some MSD Street Fire wires that are only 500 ohms per foot. I know a bit
about electricity, but not enough to know whether or not these wires
would enable me to run the MSD ignition and coil without the ballast
resistor. After all, the point of an MSD ignition upgrade is to get
longer stronger spark to the plug.
Low resistance actually doesn't help in most cases, probably because
it slows the rise time (turn-on) of the current, and I've heard of
many people running into trouble when they switched to low-resistance
plug wires.

High voltage leakage shouldn't be a problem with modern (1980s and
later) distributor caps, rotors, and wires. On the other hand after I
installed a CD ignition in my 1975 Dodge Dart, 2 caps cracked in a few
months. A slight modification to limit the primary voltage to under
400V stopped this.
D***@yahoo.com
2008-12-31 16:34:19 UTC
Permalink
I would suspect that too much primary current just supersaturates the
coil and it doesn't discharge properly, inhibiting the next charge/
discharge cycle.

Dan
HLS
2008-12-31 18:29:32 UTC
Permalink
Post by d***@my-deja.com
Low resistance actually doesn't help in most cases, probably because
it slows the rise time (turn-on) of the current, and I've heard of
many people running into trouble when they switched to low-resistance
plug wires.
I suspect the pure resistance is less of a factor than the distributed
impedance, wouldnt you
imagine?
Scott Dorsey
2008-12-31 20:19:29 UTC
Permalink
Post by HLS
Post by d***@my-deja.com
Low resistance actually doesn't help in most cases, probably because
it slows the rise time (turn-on) of the current, and I've heard of
many people running into trouble when they switched to low-resistance
plug wires.
I suspect the pure resistance is less of a factor than the distributed
impedance, wouldnt you
imagine?
I am not really sure... I think you can look at the cable as a lumped-sum
anyway. It's pretty much just the resistance of the cable that will affect
how much the coil will ring on the tail end of the pulse, and I think that
is the big deal. The capacitance between the cable conductors and ground
COULD make a difference, but they are going to be different in every
installation depending on how the cables are laid out. The series inductance
of the cable should be minimal.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Bill Putney
2008-12-31 20:36:53 UTC
Permalink
Post by Scott Dorsey
Post by HLS
Post by d***@my-deja.com
Low resistance actually doesn't help in most cases, probably because
it slows the rise time (turn-on) of the current, and I've heard of
many people running into trouble when they switched to low-resistance
plug wires.
I suspect the pure resistance is less of a factor than the distributed
impedance, wouldnt you
imagine?
I am not really sure... I think you can look at the cable as a lumped-sum
anyway. It's pretty much just the resistance of the cable that will affect
how much the coil will ring on the tail end of the pulse, and I think that
is the big deal. The capacitance between the cable conductors and ground
COULD make a difference, but they are going to be different in every
installation depending on how the cables are laid out. The series inductance
of the cable should be minimal.
--scott
I think the whole idea behind the MSW (magneto-suppressive, spiral wound
solid wire) wires was to reduce the d.c. resistance (relative to
resistive core wires - a thing of the past) for increased spark current,
but increased inductance to keep the EMI/RFI (radio interferenece)
within reasonable limits - kind of the best of both worlds ("hotter"
spark, low radio interference).
--
Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')
HLS
2008-12-31 23:20:48 UTC
Permalink
Post by Scott Dorsey
I am not really sure... I think you can look at the cable as a lumped-sum
anyway. It's pretty much just the resistance of the cable that will affect
how much the coil will ring on the tail end of the pulse, and I think that
is the big deal.
The inductance and the capacitance form the resonant circuit. The
resistance
is related to the Q, or quality factor.

The resonant circuit is responsible for the ringing.

I believe, anyway>)
Scott Dorsey
2008-12-31 23:33:53 UTC
Permalink
Post by HLS
Post by Scott Dorsey
I am not really sure... I think you can look at the cable as a lumped-sum
anyway. It's pretty much just the resistance of the cable that will affect
how much the coil will ring on the tail end of the pulse, and I think that
is the big deal.
The inductance and the capacitance form the resonant circuit. The
resistance
is related to the Q, or quality factor.
Yes, but the thing is that the coil inductance and the distributed
inductance of the coil are so enormous that the cable doesn't contribute
a whole lot. The cable impedance is pretty heavily swamped.

Someone mentioned spiral-wound cables for RF suppression... I have never
used such a thing, but they could have enough series inductance to change
things. The most important part of that is that they will be a low
pass filter.
Post by HLS
The resonant circuit is responsible for the ringing.
I believe, anyway>)
It is, but the coil resonance itself is so substantial that the cable
shouldn't change it TOO much.

It would be fun to measure it with a scope, though, and see how changing
the cable length alters the waveform. It bet it doesn't do much, but it
would be fun to see.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Jack
2008-12-31 21:45:11 UTC
Permalink
Post by d***@my-deja.com
Post by Jack
1987 Dodge Dakota 3.9L carbed
I recently posted on rec.autos.tech about the problems I was having with
an MSD 5900 Blaster ignition and an MSD 8202 Baster 2 coil. It seems I
could use one or the other with no problem, either the MSD ignition with
the stock coil or the MSD coil with the stock ignition, but if I had
both installed I would get a stumble on accelerating from a dead stop.
From this behavior I deduced that, for some reason, the problem was
being caused by too much ignition voltage. To test out that theory I
installed a 1 ohm ballast resistor in line with the +12 volts going to
the coil. Voila, the problem vanished and I was back to strong, smooth
acceleration from a dead stop. So then I tried a 1/2 ohm ballast
resistor and the stumble returned, but not as bad, so I went back to the
1 ohm resistor.
The stock coil has about a 1.5 ohm primary and the MSD coil has a .7 ohm
or so primary. I don't know what impact this has on the situation but
it's info that I have and I figured I might as well throw it in if I am
going to all the trouble of posting this and you are going to all the
trouble of reading it.
I'm going to say MSD designed the output section of their ignition
system wrong, and maybe when the resistance is low, it goes into
current-limiting mode to protect itself. Another possibility is the
high voltage protection for the output section (typically some zener
diodes and capacitor) is interacting badly with the coil primary.
MSD recommends that these two units be used together on an ignition
system such as the one in the 87 Dodge Dakota 3.9L. I am not saying that
this means squat, just that this is their recommendation. The MSD
ignition alone was causing the stock coil to get so hot that I could not
keep my fingers on for more than a second after a good run, which is why
I got the coil that MSD recommends.
Post by d***@my-deja.com
Post by Jack
Now we get to meat of the my puzzlement. The ignition wires that I have
on the engine measure about 3000 ohms per foot. For about $45 I can buy
some MSD Street Fire wires that are only 500 ohms per foot. I know a bit
about electricity, but not enough to know whether or not these wires
would enable me to run the MSD ignition and coil without the ballast
resistor. After all, the point of an MSD ignition upgrade is to get
longer stronger spark to the plug.
Low resistance actually doesn't help in most cases, probably because
it slows the rise time (turn-on) of the current, and I've heard of
many people running into trouble when they switched to low-resistance
plug wires.
High voltage leakage shouldn't be a problem with modern (1980s and
later) distributor caps, rotors, and wires. On the other hand after I
installed a CD ignition in my 1975 Dodge Dart, 2 caps cracked in a few
months. A slight modification to limit the primary voltage to under
400V stopped this.
Ah, this interesting. How did you accomplish this, if I might ask? MSD
specs the 5900 as producing 420-450 volts to the primary. The stock 12+
wire to coil remains and MSD adds another wire from the ignition unit to
the + coil terminal and replaces the signal wire from the computer with
another wire from the unit and the stock signal wire is connected to a
third wire from the unit. A fourth wire goes to ground. Here is a link
to a PDF file of the wiring instructions for the unit:

http://www.msdignition.com/uploadedFiles/MSDIgnitioncom/Products/Ignitions/5900_instructions.pdf

Figure 2 is the one that applies.

How might I lower the voltage as you have, rather than installing a
ballast resistor in the +12 volt wire to the coil.

Oh, and thanks for sending the schematics for the different ignition
systems. Now that I have my system stabilized and running well, I plan
to check them out in detail.

Jack
Mike
2009-01-02 18:52:08 UTC
Permalink
Post by Jack
Post by d***@my-deja.com
Post by Jack
1987 Dodge Dakota 3.9L carbed
I recently posted on rec.autos.tech about the problems I was having with
an MSD 5900 Blaster ignition and an MSD 8202 Baster 2 coil. It seems I
could use one or the other with no problem, either the MSD ignition with
the stock coil or the MSD coil with the stock ignition, but if I had
both installed I would get a stumble on accelerating from a dead stop.
From this behavior I deduced that, for some reason, the problem was
being caused by too much ignition voltage. To test out that theory I
installed a 1 ohm ballast resistor in line with the +12 volts going to
the coil. Voila, the problem vanished and I was back to strong, smooth
acceleration from a dead stop. So then I tried a 1/2 ohm ballast
resistor and the stumble returned, but not as bad, so I went back to the
1 ohm resistor.
The stock coil has about a 1.5 ohm primary and the MSD coil has a .7 ohm
or so primary. I don't know what impact this has on the situation but
it's info that I have and I figured I might as well throw it in if I am
going to all the trouble of posting this and you are going to all the
trouble of reading it.
I'm going to say MSD designed the output section of their ignition
system wrong, and maybe when the resistance is low, it goes into
current-limiting mode to protect itself. Another possibility is the
high voltage protection for the output section (typically some zener
diodes and capacitor) is interacting badly with the coil primary.
MSD recommends that these two units be used together on an ignition
system such as the one in the 87 Dodge Dakota 3.9L. I am not saying that
this means squat, just that this is their recommendation. The MSD
ignition alone was causing the stock coil to get so hot that I could not
keep my fingers on for more than a second after a good run, which is why
I got the coil that MSD recommends.
Post by d***@my-deja.com
Post by Jack
Now we get to meat of the my puzzlement. The ignition wires that I have
on the engine measure about 3000 ohms per foot. For about $45 I can buy
some MSD Street Fire wires that are only 500 ohms per foot. I know a bit
about electricity, but not enough to know whether or not these wires
would enable me to run the MSD ignition and coil without the ballast
resistor. After all, the point of an MSD ignition upgrade is to get
longer stronger spark to the plug.
Low resistance actually doesn't help in most cases, probably because
it slows the rise time (turn-on) of the current, and I've heard of
many people running into trouble when they switched to low-resistance
plug wires.
High voltage leakage shouldn't be a problem with modern (1980s and
later) distributor caps, rotors, and wires. On the other hand after I
installed a CD ignition in my 1975 Dodge Dart, 2 caps cracked in a few
months. A slight modification to limit the primary voltage to under
400V stopped this.
Ah, this interesting. How did you accomplish this, if I might ask? MSD
specs the 5900 as producing 420-450 volts to the primary. The stock 12+
wire to coil remains and MSD adds another wire from the ignition unit to
the + coil terminal and replaces the signal wire from the computer with
another wire from the unit and the stock signal wire is connected to a
third wire from the unit. A fourth wire goes to ground. Here is a link
http://www.msdignition.com/uploadedFiles/MSDIgnitioncom/Products/Ignitions/5900_instructions.pdf
Figure 2 is the one that applies.
Shouldn't you be using figure 4 for your truck, unless you have switched to
a points distributor ? Have you tried wiring it using figure 4 to see if it
would run any better ?
Jack
2009-01-02 20:11:51 UTC
Permalink
Post by Mike
Post by Jack
Post by d***@my-deja.com
Post by Jack
1987 Dodge Dakota 3.9L carbed
I recently posted on rec.autos.tech about the problems I was having with
an MSD 5900 Blaster ignition and an MSD 8202 Baster 2 coil. It seems I
could use one or the other with no problem, either the MSD ignition with
the stock coil or the MSD coil with the stock ignition, but if I had
both installed I would get a stumble on accelerating from a dead stop.
From this behavior I deduced that, for some reason, the problem was
being caused by too much ignition voltage. To test out that theory I
installed a 1 ohm ballast resistor in line with the +12 volts going to
the coil. Voila, the problem vanished and I was back to strong, smooth
acceleration from a dead stop. So then I tried a 1/2 ohm ballast
resistor and the stumble returned, but not as bad, so I went back to the
1 ohm resistor.
The stock coil has about a 1.5 ohm primary and the MSD coil has a .7 ohm
or so primary. I don't know what impact this has on the situation but
it's info that I have and I figured I might as well throw it in if I am
going to all the trouble of posting this and you are going to all the
trouble of reading it.
I'm going to say MSD designed the output section of their ignition
system wrong, and maybe when the resistance is low, it goes into
current-limiting mode to protect itself. Another possibility is the
high voltage protection for the output section (typically some zener
diodes and capacitor) is interacting badly with the coil primary.
MSD recommends that these two units be used together on an ignition
system such as the one in the 87 Dodge Dakota 3.9L. I am not saying that
this means squat, just that this is their recommendation. The MSD
ignition alone was causing the stock coil to get so hot that I could not
keep my fingers on for more than a second after a good run, which is why
I got the coil that MSD recommends.
Post by d***@my-deja.com
Post by Jack
Now we get to meat of the my puzzlement. The ignition wires that I have
on the engine measure about 3000 ohms per foot. For about $45 I can buy
some MSD Street Fire wires that are only 500 ohms per foot. I know a bit
about electricity, but not enough to know whether or not these wires
would enable me to run the MSD ignition and coil without the ballast
resistor. After all, the point of an MSD ignition upgrade is to get
longer stronger spark to the plug.
Low resistance actually doesn't help in most cases, probably because
it slows the rise time (turn-on) of the current, and I've heard of
many people running into trouble when they switched to low-resistance
plug wires.
High voltage leakage shouldn't be a problem with modern (1980s and
later) distributor caps, rotors, and wires. On the other hand after I
installed a CD ignition in my 1975 Dodge Dart, 2 caps cracked in a few
months. A slight modification to limit the primary voltage to under
400V stopped this.
Ah, this interesting. How did you accomplish this, if I might ask? MSD
specs the 5900 as producing 420-450 volts to the primary. The stock 12+
wire to coil remains and MSD adds another wire from the ignition unit to
the + coil terminal and replaces the signal wire from the computer with
another wire from the unit and the stock signal wire is connected to a
third wire from the unit. A fourth wire goes to ground. Here is a link
http://www.msdignition.com/uploadedFiles/MSDIgnitioncom/Products/Ignitions/5900_instructions.pdf
Figure 2 is the one that applies.
Shouldn't you be using figure 4 for your truck, unless you have switched to
a points distributor ? Have you tried wiring it using figure 4 to see if it
would run any better ?
That's what I thought when I first got the unit over a year and half ago
and that's the way that I first wired it up. Didn't start that way. I
got nothing but cranking when I turned the key to start. Again, MSD is
totally remiss in their instructions about wiring up a *Hall effect*
pickup as opposed to a *magnetic* pickup. One has to dig into their
forums to discover that a Hall effect pickup is wired the same as a
points system and not as a magnetic pickup system.

Notice that a Hall effect pickup is not mentioned in the wiring
instructions. However, preceding the Figure 2 diagram is a key to the
colored wires of the 5900 unit. Notice that the white wire is for
"Points or *electronic ignition trigger*". On my truck, 87 Dak with 3.9L
engine, the Hall effect signal from the distributor is sent to the spark
control computer where it is processed and amplified and then sent to
the coil. This is the same signal that a points system sends directly to
the coil and, after much frustration and finally an email to MSD, I
realized is the "electronic ignition trigger" referred to in the
instructions. Both are to be connected to the white wire.

I can only assume from the wiring setup in Figure 4 that the signal from
the *magnetic pickup* is already processed with spark advance
information inside the distributer, as there is no provision for it once
the wiring harness from the distributor is disconnected. The 5900 has no
timing processing, just firing from a signal fed to it. This puzzled me
at the time that I tried to use that wiring scheme, but it seemed like
the one to use at the time.

The following from an MSD tech spells out how to wire up a Hall effect
pickup to an MSD ignition. The unit is different from the 5900, but the
principal is the same:

"If this is a Hall Effect Pick up, then you can use the white wire of
the MSD Unit. The white wire is an input that can be triggered through a
point or amplified style pick up, such as a hall effect. The other
method is a magnetic pick up. Thanks, msdtech2"

https://www.msdignition.com/forum/showthread.php?t=653
ben91932
2009-01-01 05:20:20 UTC
Permalink
Post by Jack
1987 Dodge Dakota 3.9L carbed
I recently posted on rec.autos.tech about the problems I was having with
an MSD 5900 Blaster ignition and an MSD 8202 Baster 2 coil. It seems I
could use one or the other with no problem, either the MSD ignition with
2 ppm HC is easy.
Retard the timing 2 degrees and it will drop right down...
Just to cover the bases...
Is the Cat OK? a temp gun should show a hotter outlet than inlet.
Does it run hot enough? No 160 TStat?
Absolutely no misfires? A dollar bill held up to the exhaust should
not vibrate.
HTH,
Ben
Jack
2009-01-01 05:33:12 UTC
Permalink
Post by ben91932
Post by Jack
1987 Dodge Dakota 3.9L carbed
I recently posted on rec.autos.tech about the problems I was having with
an MSD 5900 Blaster ignition and an MSD 8202 Baster 2 coil. It seems I
could use one or the other with no problem, either the MSD ignition with
2 ppm HC is easy.
Retard the timing 2 degrees and it will drop right down...
Just to cover the bases...
Is the Cat OK? a temp gun should show a hotter outlet than inlet.
Does it run hot enough? No 160 TStat?
Absolutely no misfires? A dollar bill held up to the exhaust should
not vibrate.
HTH,
Ben
Thanks, Ben, I'll definitely keep that in mind when the time comes.
5 BTDC shouldn't look that much different from 7 BTDC.

There has been an annoying misfire at idle for quite some time, although
with the current ignition system that I described elsewhere on the
thread, the idle seems to have smoothed out considerably. But the smog
test I have to take doesn't cover idle. It covers 15 and 25 mph on a
dynamometer. Sometime in the next week or two I am going to get a dry
run at the smog shop to see what it's reading.
m***@yahoo.com
2009-01-01 20:57:35 UTC
Permalink
Post by Jack
Post by ben91932
Post by Jack
1987 Dodge Dakota 3.9L carbed
I recently posted on rec.autos.tech about the problems I was having with
an MSD 5900 Blaster ignition and an MSD 8202 Baster 2 coil. It seems I
could use one or the other with no problem, either the MSD ignition with
2 ppm HC is easy.
Retard the timing 2 degrees and it will drop right down...
Just to cover the bases...
Is the Cat OK? a temp gun should show a hotter outlet than inlet.
Does it run hot enough? No 160 TStat?
Absolutely no misfires? A dollar bill held up to the exhaust should
not vibrate.
HTH,
Ben
Thanks, Ben, I'll definitely keep that in mind when the time comes.
5 BTDC shouldn't look that much different from 7 BTDC.
There has been an annoying misfire at idle for quite some time, although
with the current ignition system that I described elsewhere on the
thread, the idle seems to have smoothed out considerably. But the smog
test I have to take doesn't cover idle. It covers 15 and 25 mph on a
dynamometer. Sometime in the next week or two I am going to get a dry
run at the smog shop to see what it's reading.- Hide quoted text -
- Show quoted text -
Jack,

from readin gall the above posts, my GUESS is that the combination
taht casues the stumble is for some reason casuing a WEAK spark. As
one poster said, it is hardest to develop spark during acceleration
when compression is the highest, so I guess there is some interaction
in the electronics and the coil such that you have a poor spark at
that time. Somehow the 1 Ohm ballast cures the interaction. I would
leave the 1 Ohm in the circuit and be happy, but if you want to
analyze this further I agree with another postr, you will need a scope
or ignition analyzer to look at the SECONDARY waveforms and see just
what is going on with and without the ballast.

also as far as I know, the purpose of resistance plug wires is to
reduce radio interference. They don't really lower or raise the
voltage of the spark AT THE PLUG.

You are doing a great job at narrowing in on this.. but I think you
need a scope to get to the next step.

Mark
Jack
2009-01-01 22:40:45 UTC
Permalink
Post by m***@yahoo.com
Post by Jack
Post by ben91932
Post by Jack
1987 Dodge Dakota 3.9L carbed
I recently posted on rec.autos.tech about the problems I was having with
an MSD 5900 Blaster ignition and an MSD 8202 Baster 2 coil. It seems I
could use one or the other with no problem, either the MSD ignition with
2 ppm HC is easy.
Retard the timing 2 degrees and it will drop right down...
Just to cover the bases...
Is the Cat OK? a temp gun should show a hotter outlet than inlet.
Does it run hot enough? No 160 TStat?
Absolutely no misfires? A dollar bill held up to the exhaust should
not vibrate.
HTH,
Ben
Thanks, Ben, I'll definitely keep that in mind when the time comes.
5 BTDC shouldn't look that much different from 7 BTDC.
There has been an annoying misfire at idle for quite some time, although
with the current ignition system that I described elsewhere on the
thread, the idle seems to have smoothed out considerably. But the smog
test I have to take doesn't cover idle. It covers 15 and 25 mph on a
dynamometer. Sometime in the next week or two I am going to get a dry
run at the smog shop to see what it's reading.- Hide quoted text -
- Show quoted text -
Jack,
from readin gall the above posts, my GUESS is that the combination
taht casues the stumble is for some reason casuing a WEAK spark. As
one poster said, it is hardest to develop spark during acceleration
when compression is the highest, so I guess there is some interaction
in the electronics and the coil such that you have a poor spark at
that time. Somehow the 1 Ohm ballast cures the interaction. I would
leave the 1 Ohm in the circuit and be happy, but if you want to
analyze this further I agree with another postr, you will need a scope
or ignition analyzer to look at the SECONDARY waveforms and see just
what is going on with and without the ballast.
also as far as I know, the purpose of resistance plug wires is to
reduce radio interference. They don't really lower or raise the
voltage of the spark AT THE PLUG.
You are doing a great job at narrowing in on this.. but I think you
need a scope to get to the next step.
Mark
Thanks, Mark for the encouragement. I am *more* than happy with the
ballast resistor. After I got things working right by putting one in the
system, I googled "ballast" at the msdigntion.com/forum site:

http://www.google.com/search?sourceid=chrome&ie=UTF-8&q=ballast+site:msdignition.com/forum

and came up with a whole slew of posts regarding using a ballast
resistor to compensate for the low primary resistance of the MSD coil
when used on a mechanical distributor ignition that uses a magnetic or
Hall effect pickup and electronics to fire the coil. The primary of the
MSD coil is .7 ohms and the replacement stock coil that I had been using
was 1.7 ohms measured with a digital meter.

MSD mentions nothing in their instruction sheet for the coil or ignition
about using a ballast resistor except when points are involved. Neither
is this info on any of the pages of their website except buried in the
forums in answer to questions of people who are trying to install their
units. So, according to the advice of the MSD techs, I did the correct
thing, but it sure would have been a helluva lot less time and nerve
consuming had they discussed the need for a ballast resistor in a
non-points distributor in their instructions.

In all the advice to people asking about this the techs would invariably
state that *NOT* using a ballast resistor could result in the failure of
the electronics that fires the coil in non-points systems. You would
think that a company like MSD would be more thorough in explaining in
their installation instructions the correct way to wire up their units
without causing damage to your vehicles electronics, but here we are.

I'm glad I held off buying low resistance wires. It didn't make sense to
me that they would correct the problem I was having.
z
2009-01-09 06:30:23 UTC
Permalink
Post by Jack
Post by m***@yahoo.com
Post by Jack
Post by ben91932
Post by Jack
1987 Dodge Dakota 3.9L carbed
I recently posted on rec.autos.tech about the problems I was having with
an MSD 5900 Blaster ignition and an MSD 8202 Baster 2 coil. It seems I
could use one or the other with no problem, either the MSD ignition with
2 ppm HC is easy.
Retard the timing 2 degrees and it will drop right down...
Just to cover the bases...
Is the Cat OK? a temp gun should show a hotter outlet than inlet.
Does it run hot enough? No 160 TStat?
Absolutely no misfires? A dollar bill held up to the exhaust should
not vibrate.
HTH,
Ben
Thanks, Ben, I'll definitely keep that in mind when the time comes.
5 BTDC shouldn't look that much different from 7 BTDC.
There has been an annoying misfire at idle for quite some time, although
with the current ignition system that I described elsewhere on the
thread, the idle seems to have smoothed out considerably. But the smog
test I have to take doesn't cover idle. It covers 15 and 25 mph on a
dynamometer. Sometime in the next week or two I am going to get a dry
run at the smog shop to see what it's reading.- Hide quoted text -
- Show quoted text -
Jack,
from readin gall the above posts, my GUESS is that the combination
taht casues the stumble is for some reason casuing a WEAK spark.  As
one poster said, it is hardest to develop spark during acceleration
when compression is the highest, so I guess there is some interaction
in the electronics and the coil such that you have a poor spark at
that time.   Somehow the 1 Ohm ballast cures the interaction.  I would
leave the 1 Ohm in the circuit and be happy, but if you want to
analyze this further I agree with another postr, you will need a scope
or ignition analyzer to look at the SECONDARY waveforms and see just
what is going on with and without the ballast.
also as far as  I know, the purpose of resistance plug wires is to
reduce radio interference.  They don't really lower or raise the
voltage of the spark AT THE PLUG.
You are doing a great job at narrowing  in on this.. but I think you
need a scope to get to the next step.
Mark
Thanks, Mark for the encouragement. I am *more* than happy with the
ballast resistor. After I got things working right by putting one in the
http://www.google.com/search?sourceid=chrome&ie=UTF-8&q=ballast+site:...
and came up with a whole slew of posts regarding using a ballast
resistor to compensate for the low primary resistance of the MSD coil
when used on a mechanical distributor ignition that uses a magnetic or
Hall effect pickup and electronics to fire the coil. The primary of the
MSD coil is .7 ohms and the replacement stock coil that I had been using
was 1.7 ohms measured with a digital meter.
MSD mentions nothing in their instruction sheet for the coil or ignition
about using a ballast resistor except when points are involved. Neither
is this info on any of the pages of their website except buried in the
forums in answer to questions of people who are trying to install their
units. So, according to the advice of the MSD techs, I did the correct
thing, but it sure would have been a helluva lot less time and nerve
consuming had they discussed the need for a ballast resistor in a
non-points distributor in their instructions.
In all the advice to people asking about this the techs would invariably
state that *NOT* using a ballast resistor could result in the failure of
the electronics that fires the coil in non-points systems. You would
think that a company like MSD would be more thorough in explaining in
their installation instructions the correct way to wire up their units
without causing damage to your vehicles electronics, but here we are.
I'm glad I held off buying low resistance wires. It didn't make sense to
me that they would correct the problem I was having.- Hide quoted text -
- Show quoted text -
in addition, looking at the pdf of the instruction sheet, the fact
that they specify those squeeze on connectors that bite through the
insulation worries me. i've used them quite a bit but they are
problematic on several levels and their use in a supposed high-class
high-performance etc. product kind of sits me back a minute, and that
combined with the lack of proper support you're mentioning really
makes me wonder about these guys. even if their basic engineering is
good, it seems their applications and marketing torpedoes the whole
ship.
Bob AZ
2009-01-12 06:12:57 UTC
Permalink
looking at the pdf of the instruction sheet, the fact
Post by z
that they specify those squeeze on connectors that bite through the
insulation worries me. i've used them quite a bit but they are
problematic on several levels and their use in a supposed high-class
high-performance etc.
I had a 72 Dodge 318 PU that I replaced the ignition with a later
Dodge Van electronic ignition. I had squeeze on connector problems
with it after a few years. I replaced everything with Mil Spec
connectors and all was OK.

product kind of sits me back a minute, and that
Post by z
combined with the lack of proper support you're mentioning really
makes me wonder about these guys. even if their basic engineering is
good, it seems their applications and marketing torpedoes the whole
ship.
These are my thoughts also. Too many aftermarket products,
particularly electronic, are market by folks who know little about
their products. There are a few who do but they alwys turn out to be
manufactured by Industry leaders like Bendix, Delco and the like. The
ones that the big three turn to with problems. Like the brakes on my
Chevrolet P30 RV chassis.

Bob AZ
Bill Putney
2009-01-12 11:06:48 UTC
Permalink
Post by Bob AZ
I had a 72 Dodge 318 PU that I replaced the ignition with a later
Dodge Van electronic ignition. I had squeeze on connector problems
with it after a few years. I replaced everything with Mil Spec
connectors and all was OK...
A lot of time the problem with the insulation displacement type
connectors is that people don't pay attention to the proper size (red,
blue, or yellow) for the gage of wire. That is particularly a problem
with using one made for bigger wire on smaller wire (say, blue connector
good for up to 18 ga wire but used on 20 or 22 gage wire). But, yeah,
otherwise, due to exposure to air and moisture, they are not nearly as
reliable over the long term as a soldered or crimped-and-soldered
connection. Crimped (no solder) is good if done right - i.e., right
size connector for the gage of wire, and good quality crimp tools - none
of this squeeze it flat with pliers routine.

So much about making connections is dependent on the skill and care of
the person doing the work. Shipping typical consumer (poor) quality
connectors to be installed by the typical consumer is a recipe for poor
reliability. But the typical consumer wants quick and easy vs. takes a
little time and care to do, and the manufacturer/marketer wants low cost
and to make it easy for what he knows is his ignorant, cheap, and
impatient consumer (not saying you are any of those - just generalizing).

If they put better type connectors in the kit, they may lose sales due
to cost or higher skill levels required for installation (and you could
credibly argue that they eventually lose sales due to poor reliability
with cheap connectors, but unfortunately the company who cheaps out will
probably have the overall better profitability record (in today's
ebay/consumer market).
--
Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')
Bob AZ
2009-01-12 15:56:51 UTC
Permalink
Post by Bill Putney
A lot of time the problem with the insulation displacement type
connectors is that people don't pay attention to the proper size (red,
blue, or yellow) for the gage of wire. �That is particularly a problem
with using one made for bigger wire on smaller wire (say, blue connector
good for up to 18 ga wire but used on 20 or 22 gage wire). �But, yeah,
otherwise, due to exposure to air and moisture, they are not nearly as
reliable over the long term as a soldered or crimped-and-soldered
connection. �Crimped (no solder) is good if done right - i.e., right
size connector for the gage of wire, and good quality crimp tools - none
of this squeeze it flat with pliers routine.
Bill

Just a tip that many might use.

When faced with using a too large terminal just strip the wire a
little more than twice as long as needed, bend the wire over double
and then crimp in place. IOW use the additional wire as a filler.

I also agree on using the proper crimp tool. I do hate those cheap
ones like the brand name "Crimp". Fortunately in many years I have
collected enough crimping tools that I can do almost all of them.

And also there was a thread seveal years agou about whether to solder
and crimp or just crimp. Related to mostly battery cables. It was
noted that GM crimped only. Less trouble with corrosion as in green
stuff. The connection then needs to be sealed.

Bob AZ
Bill Putney
2009-01-12 22:58:52 UTC
Permalink
Post by Bob AZ
Post by Bill Putney
A lot of time the problem with the insulation displacement type
connectors is that people don't pay attention to the proper size (red,
blue, or yellow) for the gage of wire. �That is particularly a problem
with using one made for bigger wire on smaller wire (say, blue connector
good for up to 18 ga wire but used on 20 or 22 gage wire). �But, yeah,
otherwise, due to exposure to air and moisture, they are not nearly as
reliable over the long term as a soldered or crimped-and-soldered
connection. �Crimped (no solder) is good if done right - i.e., right
size connector for the gage of wire, and good quality crimp tools - none
of this squeeze it flat with pliers routine.
Bill
Just a tip that many might use.
When faced with using a too large terminal just strip the wire a
little more than twice as long as needed, bend the wire over double
and then crimp in place. IOW use the additional wire as a filler.
I also agree on using the proper crimp tool. I do hate those cheap
ones like the brand name "Crimp". Fortunately in many years I have
collected enough crimping tools that I can do almost all of them.
And also there was a thread seveal years agou about whether to solder
and crimp or just crimp. Related to mostly battery cables. It was
noted that GM crimped only. Less trouble with corrosion as in green
stuff. The connection then needs to be sealed.
Bob AZ
Good suggestion about doubling up on the wire, Bob - I think I've done
that myself a couple of times - didn't actually double it over, but
stuck a second piece of wire in there.

For sealing a crimped or plain soldered connection, I've taken
electrical grade (acetic acid-free) silicone sealer and covered the
joint with it, then slid a piece of shrink tubing over it and shrunk the
shrink tubing - fun watching the excess get squoze out. Wiped off
whatever squeezed out. I think I got that idea from my Dad when I was a
kid - I think that's how they did wire splicing with submersible pumps
when they were a new item - maybe still do. The pumps came with the
splice kit including the sealer - that was in a time when your typical
silicone sealer had acetic acid in it, so the acetic acid-free type was
provided with the kit.
--
Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')
Nate Nagel
2009-01-13 00:07:47 UTC
Permalink
Post by Bill Putney
Post by Bob AZ
Post by Bill Putney
A lot of time the problem with the insulation displacement type
connectors is that people don't pay attention to the proper size (red,
blue, or yellow) for the gage of wire. �That is particularly a problem
with using one made for bigger wire on smaller wire (say, blue connector
good for up to 18 ga wire but used on 20 or 22 gage wire). �But, yeah,
otherwise, due to exposure to air and moisture, they are not nearly as
reliable over the long term as a soldered or crimped-and-soldered
connection. �Crimped (no solder) is good if done right - i.e., right
size connector for the gage of wire, and good quality crimp tools - none
of this squeeze it flat with pliers routine.
Bill
Just a tip that many might use.
When faced with using a too large terminal just strip the wire a
little more than twice as long as needed, bend the wire over double
and then crimp in place. IOW use the additional wire as a filler.
I also agree on using the proper crimp tool. I do hate those cheap
ones like the brand name "Crimp". Fortunately in many years I have
collected enough crimping tools that I can do almost all of them.
And also there was a thread seveal years agou about whether to solder
and crimp or just crimp. Related to mostly battery cables. It was
noted that GM crimped only. Less trouble with corrosion as in green
stuff. The connection then needs to be sealed.
Bob AZ
Good suggestion about doubling up on the wire, Bob - I think I've done
that myself a couple of times - didn't actually double it over, but
stuck a second piece of wire in there.
For sealing a crimped or plain soldered connection, I've taken
electrical grade (acetic acid-free) silicone sealer and covered the
joint with it, then slid a piece of shrink tubing over it and shrunk the
shrink tubing - fun watching the excess get squoze out. Wiped off
whatever squeezed out. I think I got that idea from my Dad when I was a
kid - I think that's how they did wire splicing with submersible pumps
when they were a new item - maybe still do. The pumps came with the
splice kit including the sealer - that was in a time when your typical
silicone sealer had acetic acid in it, so the acetic acid-free type was
provided with the kit.
Once upon a time I had a job (briefly) for an automotive supplier and
occasionally would have to fabricate/repair wiring harnesses for test
vehicles that weren't off the shelf parts. The way I was shown to
weatherseal a soldered wire connection was to use silicone *grease*
under the heat shrink. Sometimes connections would be potted in 5-min
epoxy as well, e.g. multi-pin connectors. I hadn't thought of using
slow-curing silicone sealant, but that seems more elegant if anything.

nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
Bill Putney
2009-01-13 00:12:30 UTC
Permalink
Post by Nate Nagel
Post by Bill Putney
Post by Bob AZ
Post by Bill Putney
A lot of time the problem with the insulation displacement type
connectors is that people don't pay attention to the proper size (red,
blue, or yellow) for the gage of wire. �That is particularly a problem
with using one made for bigger wire on smaller wire (say, blue connector
good for up to 18 ga wire but used on 20 or 22 gage wire). �But, yeah,
otherwise, due to exposure to air and moisture, they are not nearly as
reliable over the long term as a soldered or crimped-and-soldered
connection. �Crimped (no solder) is good if done right - i.e., right
size connector for the gage of wire, and good quality crimp tools - none
of this squeeze it flat with pliers routine.
Bill
Just a tip that many might use.
When faced with using a too large terminal just strip the wire a
little more than twice as long as needed, bend the wire over double
and then crimp in place. IOW use the additional wire as a filler.
I also agree on using the proper crimp tool. I do hate those cheap
ones like the brand name "Crimp". Fortunately in many years I have
collected enough crimping tools that I can do almost all of them.
And also there was a thread seveal years agou about whether to solder
and crimp or just crimp. Related to mostly battery cables. It was
noted that GM crimped only. Less trouble with corrosion as in green
stuff. The connection then needs to be sealed.
Bob AZ
Good suggestion about doubling up on the wire, Bob - I think I've done
that myself a couple of times - didn't actually double it over, but
stuck a second piece of wire in there.
For sealing a crimped or plain soldered connection, I've taken
electrical grade (acetic acid-free) silicone sealer and covered the
joint with it, then slid a piece of shrink tubing over it and shrunk
the shrink tubing - fun watching the excess get squoze out. Wiped off
whatever squeezed out. I think I got that idea from my Dad when I was
a kid - I think that's how they did wire splicing with submersible
pumps when they were a new item - maybe still do. The pumps came with
the splice kit including the sealer - that was in a time when your
typical silicone sealer had acetic acid in it, so the acetic acid-free
type was provided with the kit.
Once upon a time I had a job (briefly) for an automotive supplier and
occasionally would have to fabricate/repair wiring harnesses for test
vehicles that weren't off the shelf parts. The way I was shown to
weatherseal a soldered wire connection was to use silicone *grease*
under the heat shrink. Sometimes connections would be potted in 5-min
epoxy as well, e.g. multi-pin connectors. I hadn't thought of using
slow-curing silicone sealant, but that seems more elegant if anything.
nate
I never would have thought of using silicone grease either, but I could
see that working in certain situations.
--
Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')
Bryan
2009-01-13 06:05:24 UTC
Permalink
Post by Bill Putney
Post by Nate Nagel
Post by Bill Putney
Post by Bob AZ
Post by Bill Putney
A lot of time the problem with the insulation displacement type
connectors is that people don't pay attention to the proper size (red,
blue, or yellow) for the gage of wire. ?That is particularly a problem
with using one made for bigger wire on smaller wire (say, blue connector
good for up to 18 ga wire but used on 20 or 22 gage wire). ?But, yeah,
otherwise, due to exposure to air and moisture, they are not nearly as
reliable over the long term as a soldered or crimped-and-soldered
connection. ?Crimped (no solder) is good if done right - i.e., right
size connector for the gage of wire, and good quality crimp tools - none
of this squeeze it flat with pliers routine.
Bill
Just a tip that many might use.
When faced with using a too large terminal just strip the wire a
little more than twice as long as needed, bend the wire over double
and then crimp in place. IOW use the additional wire as a filler.
I also agree on using the proper crimp tool. I do hate those cheap
ones like the brand name "Crimp". Fortunately in many years I have
collected enough crimping tools that I can do almost all of them.
And also there was a thread seveal years agou about whether to solder
and crimp or just crimp. Related to mostly battery cables. It was
noted that GM crimped only. Less trouble with corrosion as in green
stuff. The connection then needs to be sealed.
Bob AZ
Good suggestion about doubling up on the wire, Bob - I think I've done
that myself a couple of times - didn't actually double it over, but
stuck a second piece of wire in there.
For sealing a crimped or plain soldered connection, I've taken
electrical grade (acetic acid-free) silicone sealer and covered the
joint with it, then slid a piece of shrink tubing over it and shrunk the
shrink tubing - fun watching the excess get squoze out. Wiped off
whatever squeezed out. I think I got that idea from my Dad when I was a
kid - I think that's how they did wire splicing with submersible pumps
when they were a new item - maybe still do. The pumps came with the
splice kit including the sealer - that was in a time when your typical
silicone sealer had acetic acid in it, so the acetic acid-free type was
provided with the kit.
Once upon a time I had a job (briefly) for an automotive supplier and
occasionally would have to fabricate/repair wiring harnesses for test
vehicles that weren't off the shelf parts. The way I was shown to
weatherseal a soldered wire connection was to use silicone *grease* under
the heat shrink. Sometimes connections would be potted in 5-min epoxy as
well, e.g. multi-pin connectors. I hadn't thought of using slow-curing
silicone sealant, but that seems more elegant if anything.
nate
I never would have thought of using silicone grease either, but I could
see that working in certain situations.
--
Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my address
with the letter 'x')
Post by Nate Nagel
Post by Bill Putney
Post by Bob AZ
Post by Bill Putney
A lot of time the problem with the insulation displacement type
connectors is that people don't pay attention to the proper size (red,
blue, or yellow) for the gage of wire. ?That is particularly a problem
with using one made for bigger wire on smaller wire (say, blue connector
good for up to 18 ga wire but used on 20 or 22 gage wire). ?But, yeah,
otherwise, due to exposure to air and moisture, they are not nearly as
reliable over the long term as a soldered or crimped-and-soldered
connection. ?Crimped (no solder) is good if done right - i.e., right
size connector for the gage of wire, and good quality crimp tools - none
of this squeeze it flat with pliers routine.
Bill
Just a tip that many might use.
When faced with using a too large terminal just strip the wire a
little more than twice as long as needed, bend the wire over double
and then crimp in place. IOW use the additional wire as a filler.
I also agree on using the proper crimp tool. I do hate those cheap
ones like the brand name "Crimp". Fortunately in many years I have
collected enough crimping tools that I can do almost all of them.
And also there was a thread seveal years agou about whether to solder
and crimp or just crimp. Related to mostly battery cables. It was
noted that GM crimped only. Less trouble with corrosion as in green
stuff. The connection then needs to be sealed.
Bob AZ
Good suggestion about doubling up on the wire, Bob - I think I've done
that myself a couple of times - didn't actually double it over, but
stuck a second piece of wire in there.
For sealing a crimped or plain soldered connection, I've taken
electrical grade (acetic acid-free) silicone sealer and covered the
joint with it, then slid a piece of shrink tubing over it and shrunk the
shrink tubing - fun watching the excess get squoze out. Wiped off
whatever squeezed out. I think I got that idea from my Dad when I was a
kid - I think that's how they did wire splicing with submersible pumps
when they were a new item - maybe still do. The pumps came with the
splice kit including the sealer - that was in a time when your typical
silicone sealer had acetic acid in it, so the acetic acid-free type was
provided with the kit.
Once upon a time I had a job (briefly) for an automotive supplier and
occasionally would have to fabricate/repair wiring harnesses for test
vehicles that weren't off the shelf parts. The way I was shown to
weatherseal a soldered wire connection was to use silicone *grease* under
the heat shrink. Sometimes connections would be potted in 5-min epoxy as
well, e.g. multi-pin connectors. I hadn't thought of using slow-curing
silicone sealant, but that seems more elegant if anything.
nate
I never would have thought of using silicone grease either, but I could
see that working in certain situations.
--
Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my address
with the letter 'x')
I like the ideas presented regarding sealing crimped terminals. Good stuff!
To add my $0.02 worth, I've also done the double-over (and sometimes more)
wire trick when the terminal normally fits a larger wire. I also prefer to
use a crimper like this one: http://tinyurl.com/7lcqas (Klein pn 1005).
Another way to keep moisture out of the crimp zone is to use heatshrink
tubing. You can get heatshrink w/ adhesive/sealer on the inside. A side
benefit is a little more support for the wire as it exits the crimped
terminal. When I added a second battery and wiring (front & rear) for an
electric winch to my '77 Dodge 3/4 ton pickup, I used 1/0 welding cable with
heavy-duty sealed heatshrink on the crimped terminals. Yes, the ground
cables are also now 1/0 wire! The connectors for the winch are 175A units,
and I made up a 1/0 jump-start cable w/ gnarly clips... I don't have to open
the hood to give (or get) a jump-start! :)

Bryan
Bob AZ
2009-01-02 01:58:39 UTC
Permalink
Post by Jack
Well that's it. At present, I am more than happy with the ballast
resistors. The truck runs great. Just curious as hell as to what might
be going on.
Jack
Jack

Read Dans' reply more closely.

I would suspect that too much primary current just supersaturates the
coil and it doesn't discharge properly, inhibiting the next charge/
discharge cycle.

Dan

Your post centered aound the ballast resistor selections. And Dans
post says it all. Perhaps things would be improved by a RF coil or
choke with a resistance of the same ohmage as the ballast resistor you
have determined to work well.

The secondary voltage is not really effected by the plug and or wire
resistance. Perhaps by their construction. The signal at the plugs is
really a complex Radio Frequency waveform that without a good scope
can not be interpreted. The usual monitor scope found in the garage is
not up to this.

And finally the manufacturer of your ignition should probably not be
in businees at all. They know little if anything about ignition
systems. You vehicle manufacturer should be relied on. Contact their
high performance folks for advice and guidance. Undoubly the
manufacturer maximized the performance of your original ignition.

Bob AZ
Jack
2009-01-02 04:28:48 UTC
Permalink
Post by Bob AZ
Post by Jack
Well that's it. At present, I am more than happy with the ballast
resistors. The truck runs great. Just curious as hell as to what might
be going on.
Jack
Jack
Read Dans' reply more closely.
I would suspect that too much primary current just supersaturates the
coil and it doesn't discharge properly, inhibiting the next charge/
discharge cycle.
Dan
Your post centered aound the ballast resistor selections. And Dans
post says it all. Perhaps things would be improved by a RF coil or
choke with a resistance of the same ohmage as the ballast resistor you
have determined to work well.
The secondary voltage is not really effected by the plug and or wire
resistance. Perhaps by their construction. The signal at the plugs is
really a complex Radio Frequency waveform that without a good scope
can not be interpreted. The usual monitor scope found in the garage is
not up to this.
And finally the manufacturer of your ignition should probably not be
in businees at all. They know little if anything about ignition
systems. You vehicle manufacturer should be relied on. Contact their
high performance folks for advice and guidance.
The vehicle manufacturer, Chrysler, is the one that stuck me with an
electronic feedback carburetor for which I cannot buy a replacement
mixture control solenoid.

Do you really think they would grace me with advice and guidance?

Get real.
Post by Bob AZ
Undoubly the
manufacturer maximized the performance of your original ignition.
Bob AZ
Bob AZ
2009-01-02 18:28:48 UTC
Permalink
Post by Jack
The vehicle manufacturer, Chrysler, is the one that stuck me with an
electronic feedback carburetor for which I cannot buy a replacement
mixture control solenoid.
Do you really think they would grace me with advice and guidance?
Get real.
Post by Bob AZ
Undoubly the
manufacturer maximized the performance of your original ignition.
Bob �AZ-
Jack

All things considered I do believe the manufacturer is a good source.
I have contacted Chrysler myself and received good advice. And after a
long evening conversation with a Ford Ignition Systems Engineer I am
more aware of the choices that the manufactures make.

Remember I advised to contact the manufacturers Performance folks.
They have a periodic magazine that is available by subscription. I
read all the issues at the dealer while getting my car and truck
serviced.

Chrysler, Ford and GM do make decisions as to whether parts ar
available and for how long. I did own a 87 Chrysler 5th avenue for a
number of years and I would expect to be able to locate whatever I
would need for it. Might take some time but if the demand is there the
parts are usually available.

In another instance just this past year I needed a fan blade for a 64
Dodge PU and the Chrysler dealer bent over backwards to locate one for
me. Took a few days but they called when they had the blade and there
was no charge.

Bob AZ
Jack
2009-01-02 20:21:09 UTC
Permalink
Post by Bob AZ
Post by Jack
The vehicle manufacturer, Chrysler, is the one that stuck me with an
electronic feedback carburetor for which I cannot buy a replacement
mixture control solenoid.
Do you really think they would grace me with advice and guidance?
Get real.
Post by Bob AZ
Undoubly the
manufacturer maximized the performance of your original ignition.
Bob �AZ-
Jack
All things considered I do believe the manufacturer is a good source.
I have contacted Chrysler myself and received good advice. And after a
long evening conversation with a Ford Ignition Systems Engineer I am
more aware of the choices that the manufactures make.
Remember I advised to contact the manufacturers Performance folks.
They have a periodic magazine that is available by subscription. I
read all the issues at the dealer while getting my car and truck
serviced.
Chrysler, Ford and GM do make decisions as to whether parts ar
available and for how long. I did own a 87 Chrysler 5th avenue for a
number of years and I would expect to be able to locate whatever I
would need for it. Might take some time but if the demand is there the
parts are usually available.
In another instance just this past year I needed a fan blade for a 64
Dodge PU and the Chrysler dealer bent over backwards to locate one for
me. Took a few days but they called when they had the blade and there
was no charge.
Bob AZ
Bob, you'll have to excuse me for being a jaded. I bought this truck new
and have taken very good care of it. That fact that I cannot buy a $60
replacement part that is crucial to running the truck has caused me
seemingly unending problems.

How would one find these "Performance folks" on the net?
Bob AZ
2009-01-04 10:00:44 UTC
Permalink
Post by Jack
Bob, you'll have to excuse me for being a jaded. I bought this truck new
and have taken very good care of it. That fact that I cannot buy a $60
replacement part that is crucial to running the truck has caused me
seemingly unending problems.
How would one find these "Performance folks" on the net?- Hide quoted text -
- Show quoted text -
If I remember correctly I called them from a number I got at the
dealer who had their magazine in the waiting room. I would go to the
Dodge site to locate an internet address for the Dodge Performance
people. Or ask at the service counter.

Bob AZ
NapalmHeart
2009-01-05 00:09:25 UTC
Permalink
Post by Bob AZ
Post by Jack
Bob, you'll have to excuse me for being a
jaded. I bought this truck new
and have taken very good care of it. That fact
that I cannot buy a $60
replacement part that is crucial to running the
truck has caused me
seemingly unending problems.
How would one find these "Performance folks" on
the net?- Hide quoted text -
- Show quoted text -
If I remember correctly I called them from a
number I got at the
dealer who had their magazine in the waiting
room. I would go to the
Dodge site to locate an internet address for the
Dodge Performance
people. Or ask at the service counter.
Bob AZ
You might also try these guys.
http://www.manciniracing.com/
Steve
2009-01-06 22:47:35 UTC
Permalink
Post by Jack
Bob, you'll have to excuse me for being a jaded. I bought this truck new
and have taken very good care of it. That fact that I cannot buy a $60
replacement part that is crucial to running the truck has caused me
seemingly unending problems.
Well, they can't keep EVERYETHING in production forever. I rather doubt
that I could go to a Chrysler dealer and buy a carburetor for my 1949
Plymouth Club Coupe, either ;-) Everything becomes obsolete eventually,
and you have to come up with acceptable replacements.
Post by Jack
How would one find these "Performance folks" on the net?
Chrysler's performance aftermarket segment (Mopar Peformance) can be
found at http://www.mopar.com/performance/index.html

But frankly, they're not nearly as helpful for the old-school carbureted
guys as they used to be. They're too busy selling crate versions of the
new Hemis for people to retrofit into their muscle cars (not a bad idea,
but its gotten too dominant for my tastes). And on top of that, you're
looking for parts for an 80s 2-bbl v6, not a 1969 440 Magnum.

I'd take a look at places like:

Manciniracing.com
Edelbrock.com
Summitracing.com
Jegs.com

Just off the top of my ol' noggin ;-)
Bill Putney
2009-01-06 23:09:40 UTC
Permalink
...Everything becomes obsolete eventually,
and you have to come up with acceptable replacements...
Reminds me about the old joke about the man talking about his axe: "Yep
- I've had this axe for years - best axe I've ever owned. All I've ever
had to do to it was replace the handle twice and the head once."
--
Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')
Jack
2009-01-07 02:28:05 UTC
Permalink
Post by Steve
Post by Jack
Bob, you'll have to excuse me for being a jaded. I bought this truck new
and have taken very good care of it. That fact that I cannot buy a $60
replacement part that is crucial to running the truck has caused me
seemingly unending problems.
Well, they can't keep EVERYETHING in production forever. I rather doubt
that I could go to a Chrysler dealer and buy a carburetor for my 1949
Plymouth Club Coupe, either ;-) Everything becomes obsolete eventually,
and you have to come up with acceptable replacements.
Post by Jack
How would one find these "Performance folks" on the net?
Chrysler's performance aftermarket segment (Mopar Peformance) can be
found at http://www.mopar.com/performance/index.html
But frankly, they're not nearly as helpful for the old-school carbureted
guys as they used to be. They're too busy selling crate versions of the
new Hemis for people to retrofit into their muscle cars (not a bad idea,
but its gotten too dominant for my tastes). And on top of that, you're
looking for parts for an 80s 2-bbl v6, not a 1969 440 Magnum.
Manciniracing.com
Edelbrock.com
Summitracing.com
Jegs.com
Just off the top of my ol' noggin ;-)
Thanks Steve, but I got the damn thing figured out.

I can understand the Mopar guys wanting to go where the money is.

These electronic feedback carbs must have gone on a gazillion cars and
trucks and those who bought them are left holding the bag.

But I got the non-feedback version of the Holley 6280, which is a 2280,
and finally got the MSD setup working right with the addition of a 1 ohm
ballast resistor to bring the MSD primary on the coil up to 1.7 ohms,
same as the stock coil, which seems to have made everything okay. The
damn thing runs better than new. I'm pretty sure it will pass smog, with
a little denatured alcohol and 2 degrees retarded timing.

Now that I have it running perfect, I want a new one, or at least
something with fuel injection.
Steve
2009-01-12 23:06:30 UTC
Permalink
Post by Jack
Post by Steve
Just off the top of my ol' noggin ;-)
Thanks Steve, but I got the damn thing figured out.
I can understand the Mopar guys wanting to go where the money is.
These electronic feedback carbs must have gone on a gazillion cars and
trucks and those who bought them are left holding the bag.
You think YOU'RE holding the bag.... try one of the 89-92 TBI v8
engines! That's an orphan and you can't even very well "MacGuyver" a
solution for it like you can with a carb.

The problem is that there's not only no reason for the factory to keep
supporting 80s vehicles, there's also no aftermarket interest in 80s
vehicles to cause the kind of support that you can get for 60s cars.
About the only 80s car that even raises any interest at all is the Buick
GN/GNX.
Jack
2009-01-13 06:32:01 UTC
Permalink
Post by Steve
Post by Jack
Post by Steve
Just off the top of my ol' noggin ;-)
Thanks Steve, but I got the damn thing figured out.
I can understand the Mopar guys wanting to go where the money is.
These electronic feedback carbs must have gone on a gazillion cars and
trucks and those who bought them are left holding the bag.
You think YOU'RE holding the bag.... try one of the 89-92 TBI v8
engines! That's an orphan and you can't even very well "MacGuyver" a
solution for it like you can with a carb.
The problem is that there's not only no reason for the factory to keep
supporting 80s vehicles, there's also no aftermarket interest in 80s
vehicles to cause the kind of support that you can get for 60s cars.
About the only 80s car that even raises any interest at all is the Buick
GN/GNX.
I can't believe how complex these internal combustion engines are and
how well they run when everything is operating correctly. They are truly
marvels of engineering.

At 2500 rpm, a V6 is firing each plug over 20 times a second.

Each intake and exhaust valve is opening and closing at the same rate.

125 explosions a second, all synchronized to maximize power output.

Meanwhile, the cooling system is pumping coolant throughout the engine
block and heads and through the radiator.

The power is transmitted to the wheels by another complicated system to
propel the vehicle down the road at speeds in excess of 70 miles an
hour. Thousands of different parts are involved and all must be working
correctly for the vehicle to maintain forward motion. I am truly amazed
that I don't see more vehicles broken down on the side of the road.
Steve
2009-01-13 16:41:28 UTC
Permalink
Post by Jack
At 2500 rpm, a V6 is firing each plug over 20 times a second.
Each intake and exhaust valve is opening and closing at the same rate.
125 explosions a second, all synchronized to maximize power output.
Its not a car engine, but given the stats you quoted above you should
enjoy this little read....


http://www.sandersaircraft.com/aircraft/dreadnought/One_Second_with_Dreadnought.pdf
Jack
2009-01-13 19:07:53 UTC
Permalink
Post by Steve
Post by Jack
At 2500 rpm, a V6 is firing each plug over 20 times a second.
Each intake and exhaust valve is opening and closing at the same rate.
125 explosions a second, all synchronized to maximize power output.
Its not a car engine, but given the stats you quoted above you should
enjoy this little read....
http://www.sandersaircraft.com/aircraft/dreadnought/One_Second_with_Dreadnought.pdf
Holy Crap!

Each cylinder displacement is as big as a small V6!

And there is 28 of 'em!

"Each piston has traveled 50 feet in linear distance, changing direction
100 times per second, with the total linear travel of all 28 pistons
adding up to a ¼ mile."

What controlled fury!

Look at the crew who probably serviced the carburetor:

http://www.vintagecarburetors.com/about.htm

happy looking bunch, eh?
Steve
2009-01-14 15:15:09 UTC
Permalink
Post by Jack
Post by Steve
http://www.sandersaircraft.com/aircraft/dreadnought/One_Second_with_Dreadnought.pdf
Holy Crap!
That pretty much sums up an R-4360 ;-)
Post by Jack
Each cylinder displacement is as big as a small V6!
And there is 28 of 'em!
28 cylinders, 56 spark plugs, 4 magnetos. One caburetor (actually a
hybrid called an "injection carburetor" with venturis the size of coffee
cans.
Post by Jack
"Each piston has traveled 50 feet in linear distance, changing direction
100 times per second, with the total linear travel of all 28 pistons
adding up to a ¼ mile."
What controlled fury!
In this case, controlled SEA Fury ;-)

And when those engines were installed in a B-36 or a Globemaster, they
would run *continuously* for 20+ hour missions. A B-36 had SIX 4360s,
each of which had two turbochargers in addition to its 56 plugs. That
made for one very busy flight engineer! Turbocharger wastegate,
throttle, mixture, prop pitch, and several other parameters were all set
and monitored by the FE. Good old days!

z
2009-01-09 06:26:13 UTC
Permalink
Post by Steve
Post by Jack
Bob, you'll have to excuse me for being a jaded. I bought this truck new
and have taken very good care of it. That fact that I cannot buy a $60
replacement part that is crucial to running the truck has caused me
seemingly unending problems.
Well, they can't keep EVERYETHING in production forever. I rather doubt
that I could go to a Chrysler dealer and buy a carburetor for my 1949
Plymouth Club Coupe, either ;-)  Everything becomes obsolete eventually,
and you have to come up with acceptable replacements.
time was when chrysler was famous for keeping replacement parts for
everything forever (more or less) but they had to dump this policy
after the near bankruptcy in 1980 or thereabouts. too bad.
IRONMONKEY
2009-01-13 20:00:21 UTC
Permalink
Post by Jack
1987 Dodge Dakota 3.9L carbed
I recently posted on rec.autos.tech about the problems I was having with
an MSD 5900 Blaster ignition and an MSD 8202 Baster 2 coil. It seems I
could use one or the other with no problem, either the MSD ignition with
the stock coil or the MSD coil with the stock ignition, but if I had
both installed I would get a stumble on accelerating from a dead stop.
From this behavior I deduced that, for some reason, the problem was
being caused by too much ignition voltage. To test out that theory I
installed a 1 ohm ballast resistor in line with the +12 volts going to
the coil. Voila, the problem vanished and I was back to strong, smooth
acceleration from a dead stop. So then I tried a 1/2 ohm ballast
resistor and the stumble returned, but not as bad, so I went back to the
1 ohm resistor.
The stock coil has about a 1.5 ohm primary and the MSD coil has a .7 ohm
or so primary. I don't know what impact this has on the situation but
it's info that I have and I figured I might as well throw it in if I am
going to all the trouble of posting this and you are going to all the
trouble of reading it.
Now we get to meat of the my puzzlement. The ignition wires that I have
on the engine measure about 3000 ohms per foot. For about $45 I can buy
some MSD Street Fire wires that are only 500 ohms per foot. I know a bit
about electricity, but not enough to know whether or not these wires
would enable me to run the MSD ignition and coil without the ballast
resistor. After all, the point of an MSD ignition upgrade is to get
longer stronger spark to the plug.
I don't have a clue as to why the engine stumbles with both the MSD
ignition and coil installed. From the symptoms it seems to me that it
must be because of too much voltage at the coil tower, but why that
might be causing the problem is beyond me.
Could it be because the high voltage is leaking out to ground somewhere
on the way to the plugs? I checked the engine at idle in a dark area at
night and saw no evidence of arcing. Could the high resistance wires be
the cause? If so, what is the rationale? I can't think of one.
Well that's it. At present, I am more than happy with the ballast
resistors. The truck runs great. Just curious as hell as to what might
be going on.
Jack
iron monkey,
well you should put the msd in and the coil pack in . then you should
run a NOVIS
system on your cars brain box to change the factory setting . to a
higher voltage . You can also up the fuel and air ratio , novis is a
wonderfull tool .
Jack
2009-01-13 22:23:04 UTC
Permalink
Post by IRONMONKEY
Post by Jack
1987 Dodge Dakota 3.9L carbed
I recently posted on rec.autos.tech about the problems I was having with
an MSD 5900 Blaster ignition and an MSD 8202 Baster 2 coil. It seems I
could use one or the other with no problem, either the MSD ignition with
the stock coil or the MSD coil with the stock ignition, but if I had
both installed I would get a stumble on accelerating from a dead stop.
From this behavior I deduced that, for some reason, the problem was
being caused by too much ignition voltage. To test out that theory I
installed a 1 ohm ballast resistor in line with the +12 volts going to
the coil. Voila, the problem vanished and I was back to strong, smooth
acceleration from a dead stop. So then I tried a 1/2 ohm ballast
resistor and the stumble returned, but not as bad, so I went back to the
1 ohm resistor.
The stock coil has about a 1.5 ohm primary and the MSD coil has a .7 ohm
or so primary. I don't know what impact this has on the situation but
it's info that I have and I figured I might as well throw it in if I am
going to all the trouble of posting this and you are going to all the
trouble of reading it.
Now we get to meat of the my puzzlement. The ignition wires that I have
on the engine measure about 3000 ohms per foot. For about $45 I can buy
some MSD Street Fire wires that are only 500 ohms per foot. I know a bit
about electricity, but not enough to know whether or not these wires
would enable me to run the MSD ignition and coil without the ballast
resistor. After all, the point of an MSD ignition upgrade is to get
longer stronger spark to the plug.
I don't have a clue as to why the engine stumbles with both the MSD
ignition and coil installed. From the symptoms it seems to me that it
must be because of too much voltage at the coil tower, but why that
might be causing the problem is beyond me.
Could it be because the high voltage is leaking out to ground somewhere
on the way to the plugs? I checked the engine at idle in a dark area at
night and saw no evidence of arcing. Could the high resistance wires be
the cause? If so, what is the rationale? I can't think of one.
Well that's it. At present, I am more than happy with the ballast
resistors. The truck runs great. Just curious as hell as to what might
be going on.
Jack
iron monkey,
well you should put the msd in and the coil pack in . then you should
run a NOVIS
system on your cars brain box to change the factory setting . to a
higher voltage . You can also up the fuel and air ratio , novis is a
wonderfull tool .
Novis? Never heard of it and can't find anything about it thru google.

Are you sure of the spelling?
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