Possible ignition issue, Procomp 7000 series distributor

[Milezero]

Need a little help here. 79 Lebaron, stock rebuild 360. Lean Burn delete. Running an Edelbrock AVS2 4 bbl on a stock intake (Motor and parts have maybe 2000 miles on them). The shop that did the engine swap (before my time) installed what I believe to ba a Procomp 7000 series distributor. It's got fresh plugs and Taylor wires. Here's my issue:
The car runs fine if not pushed. Under heavy acceleration, about 2 of 10 times, the motor stumbles and sputters, and has died a couple times. When it acts up, if I back off, then feather the gas a little, it usually, but not always, clears up once the PRM's drop back to no throttle speed. At first I thought it was fuel related. I've replaced the fuel tank, fuel pump, filter, blown out the fuel lines, and just rebuilt the carb. I took the time to ensure every adjustment on the carb is correct. Alas, it's still doing it!
I now suspect the issue may be ignition related, as in the cheap distributor that was installed. Does anyone have experience or comments/reviews on this distributor and it's quality? I want to go with the Mopar Electronic kit just because I've rarely had issues with them, but I'd like to retain the HEI style cap with the clip on wire ends.
Any advice or suggestions guys??

 

[BudW]

It sounds like maybe under-voltage to the ignition system. The higher the load to the engine, the more voltage needed to fire the spark plugs. I wonder if ignition has a 12 volts to it or if someone used a ballast resistor before ignition system, maybe?

I am not a big fan of the HEI style ignition system - but it seams like more and more people are going that way.
BudW

 

[Milezero]

It sounds like maybe under-voltage to the ignition system. The higher the load to the engine, the more voltage needed to fire the spark plugs. I wonder if ignition has a 12 volts to it or if someone used a ballast resistor before ignition system, maybe?

I am not a big fan of the HEI style ignition system - but it seams like more and more people are going that way.
BudW

I'm not a fan either. I've never (knock on wood) had an issue with Mom Mopar's Electronic Ignition, but I understand the new ones available today are cheaper than they used to be from a quality standpoint. The Procomp is a direct wire to the coil, and there is no ballast resistor.

 

[Aspen500]

I've got a DUI HEI on my car and it's been flawless. It's the type with a standard Mopar distributor and an HEI module and heat sink attached to the side with a remote mount coil. The BB one is like that since a large cap with integral coil is too big and won't fit.

 

[Milezero]

I've got a DUI HEI on my car and it's been flawless. It's the type with a standard Mopar distributor and an HEI module and heat sink attached to the side with a remote mount coil. The BB one is like that since a large cap with integral coil is too big and won't fit.

I’m still going back and forth between fuel and ignition issues, as I’ve never had an ignition issue before that “felt” like a fuel issue. I’m unfamiliar with the Procomp distributor that’s on it, but I understand they’re primarily Aussie designed units with a built in module. When it acts up, and I let off the accelerator, it seems to take a few seconds to clear up, then it’s fine. But everything fuel related has been replaced, cleaned, or rebuilt. I’m looking at a TSP distributor very similar to the DUI unit you run. Just don’t know if there’s anything else fuel related I’m missing.

 

[Duke5A]

The fuel lines aren't steel all the way back. Some of the bends are rubber. Give those a check if you haven't already.

 

[Oldiron440]

What do the plugs tell you?

 

[Remow2112]

Getting a timing light and a friend. With the car in park Rev to 6k rpm and see if the timing light is steady or bouncing around. I bet you will find it bouncing around. If so check the distributor and make sure the advance mechanism is free and clear. I have seen something similar with a stock dist that someone messed with the advanced weights and they were sticking.

 

[Milezero]

All rubber fuel line sections replaced. Plugs show normal wear and ideal fuel mixture. Voltage regulator is solid with 14.5-15 volts at all times. I did have way too much timing in it. Reset timing to around 14 degrees at idle. It still does it. When it acted up in the past, because I thought it was fuel related, i feathered the gas a little. This time, I just stayed in it (partial throttle). Same exact symptoms and same time for it to recover. Feels almost like a rev limiter breaking down the ignition. Think I’m gonna scrap the Procomp distributor in favor of the traditional Mopar electronic ignition. Definitely believe it’s ignition related.

 

[Milezero]

Well, Charlie Brown strikes again!! Why do we always seem to overthink things??? The button that transfers spark from the inside of the cap to the rotor is GONE! It’s arcing from the spring to the rotor. That would probably explain issue ‍
More next week, after the new cap and rotor!

 

[Milezero]

Fix O Rama! Ignition issue cleared up with a new (and complete) distributor cap. Still tinkering with timing and carb a little. Where do you guys normally run your initial timing advance? I’m running about 12 degrees right now.

 

[Milezero]

Well, I was wrong about it being “fixed”, as it acted up once again. I’ve finally found the real problem, which I apparently created myself, and have fixed it. I embarrass myself here in the hope that it helps someone in the community.
I WAS RUNNING THE WRONG COIL!
Anyone choosing to use a Procomp 7000 series distributor needs to know that your coil MUST have a primary circuit resistance of .6 to NO MORE than 1 ohm. My PS20 coil was pushing 1.5 ohms, and that’s what was creating the entire issue. Also, do not run a ballast resistor. The Procomp HEI stuff requires a full 12 volts to work properly. I put an Edelbrock coil on it (part #22746) with a primary of .7 ohms. The car hasn’t run this well since I bought it! Hope this helps someone down the road. Thank you all who offered tips and perspective. A “second set of eyes” is always appreciated!

 

[Milezero]

Well, the saga continues, and I'd like your advice. It acted up again. I've gone through the entire fuel system again, including all carb adjustments. All good.
I ordered a new ignition module, installed it, and it acted up again today, but the symptom changed a bit. Steady throttle, 3000 or so rpm, the motor acted like someone turned the ignition switch off, then on, then off, then on. Hooked up a test light to ensure I'm not losing power to the coil, and all is well. I'm stumped, but truly believe its ignition related, not fuel. I'm beginning to believe the cheap Procomp 7000 series distributor is just junk. Considered the standard Mopar electronic ignition kit, but it, now, is made by the same company (no thanks). Does anyone here have experience with the Pertronix HEI distributor, and/or prior experience with the Procomp 7000 series?

 

[Aspen500]

I'm not familiar with the Procomp but from what I can see on line, it has a pickup coil like a GM HEI. I remember problems with them when the wires to the pickup coil would break. Everytime the vacuum advance operates, the wires flex. Some would just die and not restart, others would act like it sounds yours is doing.. Cut out momentarily, then come back. If the wire is broken inside the insulation it can make contact and then go open circuit and back to making contact. It's just an idea anyway.

 

[Milezero]

I'm not familiar with the Procomp but from what I can see on line, it has a pickup coil like a GM HEI. I remember problems with them when the wires to the pickup coil would break. Everytime the vacuum advance operates, the wires flex. Some would just die and not restart, others would act like it sounds yours is doing.. Cut out momentarily, then come back. If the wire is broken inside the insulation it can make contact and then go open circuit and back to making contact. It's just an idea anyway.

You're correct, it's an old GM (Holden) HEI module. I ditched the cheap distributor and went with a Pertronics unit. It's still acting up occasionally. At this point, my best assumption is that I'm losing my 12 volt primary feed to the coil. Gonna chase the wires down and see if I've got a pinched wire or a burned end somewhere. I hate electrical Gremlins.

 

[johnnyspeed]

Need a little help here. 79 Lebaron, stock rebuild 360. Lean Burn delete. Running an Edelbrock AVS2 4 bbl on a stock intake (Motor and parts have maybe 2000 miles on them). The shop that did the engine swap (before my time) installed what I believe to ba a Procomp 7000 series distributor. It's got fresh plugs and Taylor wires. Here's my issue:
The car runs fine if not pushed. Under heavy acceleration, about 2 of 10 times, the motor stumbles and sputters, and has died a couple times. When it acts up, if I back off, then feather the gas a little, it usually, but not always, clears up once the PRM's drop back to no throttle speed. At first I thought it was fuel related. I've replaced the fuel tank, fuel pump, filter, blown out the fuel lines, and just rebuilt the carb. I took the time to ensure every adjustment on the carb is correct. Alas, it's still doing it!
I now suspect the issue may be ignition related, as in the cheap distributor that was installed. Does anyone have experience or comments/reviews on this distributor and it's quality? I want to go with the Mopar Electronic kit just because I've rarely had issues with them, but I'd like to retain the HEI style cap with the clip on wire ends.
Any advice or suggestions guys??

Have you checked the motor ground?