OK, I have been fighting this for a while now. My car keeps blowing the electronic module in the distributor. In the past year, I have had to replace that thing at least 10 times, or more! Never had this problem before with any other car. I keep an extra in the glove box, but this is getting old. Anyone have any ideas?o No:
HEI? I've always been under the impression that a bad module will damge the coil, which will in turn wipe out the new module...which is a viscous circle. Test the coil
Ah! Well, I'll try that. It makes as much sense as anything else. This is driving me nuts.:blast: Thanks, I'll let you know how it works out.
Mark, How do you know that the modules are failing. Do you get a no start condition, and replacing the module fixes it? I'm not sure there is an easy way to test them. I do know they don't like heat, hence the silicone gel you need to spread on the distributor base. I had a no start condition every once and awhile with my HEI. Replaced the module and it would start most times. I did this several times before I realized it was the pole piece that was bad. Replaced that and never had another problem.
No start. Replace the module and it starts. I'll check the pole. I'm assuming you are referring to the connectors that the module plugs into in the distributor?
Yes, The pole piece sits at the bottom of the distributor. I think they also refer to it as the pick up coil. You need to disaasemble the distributor shaft to change it. It is succeptible to heat and resistance changes. Put an ohmeter on it and check for high resistance and continuity loses as you wiggle the wires.
I also had a problem with an HEI years ago, my internally regulated Alternater would intermittently put out excessive voltage (as much as 20volts) and it would fry the HEI module. Something else to check.
I had this same problem once. There was a ground for the module under the cap that got discarded when I switched modules. I think it looked like a clip. It's been more than 10 years ago, so I don't remember the details......
Ok, folks, basic large cap junker HEI info 101. Modules will fail from a layer shorting of the primary circuit in the coil changing the resistance as the winding layers touch each other. This resistance change will make the coil force the module to work overtime and at levels it cannot sustain. Result: module after module going away, and no clear answer until out of utter frustration, you change the coil, long after the module gets all the bad rap for every problem it never really caused. Reasons: In-cap epoxy coils run much hotter than those off the cap, why do you think the feed wire is soooo large when the one feeding the module is soooo small. Heat causes resistance, and an epoxy medium will not reject heat, but wells it up, and it has a cap over it, so the heat can't get out, clever. This is why an epoxy coil feels cooler to the touch than an oil filled coil, it isn't transfering heat out of it, but retaining that heat at the windings, leaving the outer jacket fairly cool to the touch. Oil filled coils will feel significantly hotter to the touch, because they are doing their job, transferring heat away from the windings core. A pickup coil will not cause the module to fail, as the part of the module that goes away is in no way circuited to the pickup sensor circuit. A pickup coil can cause weak and/or no spark, but not kill the module. Now, to make a large cap HEI better, there is something that can be done, take that junker epoxy coil, stock or aftermarket, OUT of the cap, replace it with a nice, oil filled round coil that will live long and prosper. MSD 8401 modified coil cap Length of spiral core, magnetic suppression coil wire with correct ends Accel 8140 or 8140C coil NOTE: Don't use the MSD 8202, 8203, 8223 coils, RED Blaster II and III, they are made in a factory in Mexico that uses sub-standard windings insulating materials, and this material degrades, falls away and makes its own layer shorting. The MSD 8200 chrome Blaster II coil is still made in Indiana, is a good coil to use. And, no, the remote mounted EPOXY coils aren't any better than the ones in-cap, they are still EPOXY fileld and do not bleed heat off anywhere as well as a liquid media filled coils will. Plug gaps on any HEI .045, NO LARGER, no matter the HEI guru's recommendations for their super-zoot, ultra-volt garbage say they are the greatest things since holes in donuts, etc. Only other factors for module failure will be overvolts from regulator going nuts and making 30 alternator volts, and bad grounding to the distributor body making more resistance, which is heat, just plain resistance induced heat. High resistance in the carbon post, which is heat, high resistance in the plug wires, which would be a dead set of wires forcing the coil and module to work harder, and plug gaps way past the acceptable limit, which overloads/overworks the coil, which makes more coil heat...etc. Class dismissed.
OK ignition man, let's make this easy enough for a fireman to understand.:grin: First, I need to replace my coil with an MSD 8200. Next, check grounds which may be producing resistance. Just changed alternators, so that probably isn't it. I bet the coil replacement will do the trick. Let me try that and see how it goes. Thanks professor.
Captain You can use the Accel 8140, or 8140c, or the MSD 8200 Blaster. I bought my Accel 8140 at auto-zone $27.50 right off the shelf.:TU:
As a firefighter/paramedic, I isn't so smarts either. Where is the Pertronix Ignitor 2 coil made? Is this a quality coil or should I switch over to the MSD 8200 and paint it black to hide it?
One more thing to keep your module happy and smiling. They like heat sink grease applied to the side that is in contact with the distributor body. You might have to go find that at Radio Shack. It is heat conductive and used to transfer heat from power transistors (amplifiers) to aluminum heat sinks and chassis. And ditto on a good ground, electrical things like good grounds to keep them happy. I think Autozone has a module tester now, might try them or other stores to see if you can get a free module test. And everything IgnitionMan said.
Actually, Taiwan. It is a stock GM replacement coil, aftermarket, with stickers, and is epoxy filled to boot. Don't waste the money on the MSD 8200 coil, it is made in the same factory the Accel 8140/8140C's are in Indiana.
OK, I got my Accel 8140C last night. Now I need the new dust cover/coil cap - MSD 8401. Should get it today. Any suggestions on modules? Just a generic OK?
Dude... With what you've already spent on that HEI, and with what you're GOING to spend on it... it STILL won't offer much performance gains. You'd best cut your losses now and get a stock rebuilt conversion from Dave. You'll be miles ahead. Everyone who's done it says the idle is better, the performance is better, and the car starts so much easier...
Which Dave? Where can I get info on it? I'm actually only gonna be out about $70 bucks for everything I need. The car starts good, runs good and idles good now (when the module isn't blown!)
