Anyone have anything to suggest when I'm frying ignition modules with each start of the car almost?



I have a Pro Comp large cap HEI and have gone through three modules. I fired the car up 4 days ago and found I had a swiss cheesed radiator (How I don't know) so did not try to start it again until today when I got the new one installed. Would not start.

Knowing I had to replace the module to get it to start last time I went and bought another. Fired right up. Ran it for about 10 minutes and shut it off. Went to start it again 5 minutes later and no fire...

sounds like a grounded coil or pickupcoil or condensor. you didnt mention the module thermogrease under the module.? test the ohms on all three componants and pray one is bad. the coil and module are like buddies. if one goes bad the other will die soon after. lets just say you have a coil that fails when hot only and ruins your sweet module. you got warranty on the modules. shouldnt have to pay $$$.. and second. sounds to me its an ignition problem. you say you have a pro comp hei dizzy, would possibly the leads to the ECM match the same leads from a stock. Its got to be somthing sooo simple. Ive got a an ignition control module, two actually on hand, if you need one ill send it, BUT you should be able to claim the warranty. check your leads to ecm, test for codes. test the resistance of the coil and pick up coil, you may have a bad surge from the alternator (doubt it).

Don't know if it matters but did you double check the engine ground to the firewall?

Thanks for the helpful reply. Module grease in intact underneath. Car is converted TPI to carb so no ECM. Just a large cap HEI. I've heard the ProComps are junk but I will look into a bad coil next. Overall volts were only 12.4 at the battery when running.
[you can't test voltage in the engine bay when running because the digital meter goes crazy from some sort of interference!]

I have the engine grounded to the framerail with a 4ga strap, engine grounded directly to the relocated battery in the trunk, and battery grounded to the rear framerail with 1/0 welding lead so I think I have that covered but I may add another fro mthe motor to the firewall for good measure. Oh, I also have an extra ground strap from the alt case to the engine.

Update:

Removed ignition module and re-installed it. Car fired up fine, WTF. Alt output only 12.46v (at battery and alternator) and not increasing with RPM. 12.18v with fan running.

Shut the motor off via my kill switch and no voltage spike. Just rose back up to 12.5v.

Now I expected it not to start again since the motor got hot; tried and it started again. Will try in another 15 minutes to see what happens.

Any freakin' ideas here???

Napa part # RR231. Capacitor terminal block assy. Basically the condenser and your connectors are all made into one assembly. I'm betting something's jacked with your contacts and when you wiggle it/unplug plug it back in, it's making connection again.

Dan

Thanks Dan, that's a big help. I'm chasing all sorts of problems but that puts a little light into the no spark issue.