hei issue

[70c10stepside]

I'm onto my 5th or 6th hei control module. Cannot figure out whats going on. Has power to the battery wire and the cap has power on it where the plug hooks to it for the cap. I believe I have the correct grounds. I use the jelly. Stock like coil. Why? And when it acts up like this it runs the battery down very fast. Short maybe? Or just so happen?

[geezer#99]

You got dedicated 12v supply to the hei?

[70c10stepside]

Yes

[BIG69GMC]

How long does it take for it to go out? Maybe its the place your getting your control modules from? I know Oreillys here is not the best place for electrical parts. I used to always go thru parts often cuz they were bad quality. Maybe try getting a module from another good parts store?

[VetteVet]

Here's some things I've read about that will maybe cause the problem.

Poor quality Module
High voltage spikes from the external regulated alternator
incorrect spark plug wires
heat
coil layer shorting.

Here's a few threads on the subject.
http://www.google.com/custom?domains...D%3A1%3B&hl=en

[geezer#99]

Originally Posted by 70c10stepside

Yes

New 12 gauge wire from the Ignition switch or fuse panel I presume?

[HIGHWAY BY THE SEA]

The HEI module in my 1981 Stepside (350 engine) has done this TWICE in the last year. I have not figured out why yet...

[hayhauler71]

I have seen this happen more than a few times at work and mostly caused buy a shorting coil. I recommend replacing the coil and module with a good quality replacement.

[RustySunShine]

I doubt its a faulty part (only because you have gone through so many), maybe a new coil and/or add a ballast resister. Did you get the ICM tested? most auto parts stores have testers for those.

[yellowbomber]

Have you replaced the coil at all? When an HEI coils goes bad, even if momentary, (internal ground in coil etc), it will ALWAYS fry the module. You can replace the module only to have it fry minutes or hours later. Somtimes the coil will test fine but have a ground/short after warming up.
Vette's suggestions are all correct. If nobody has messed with the stock wiring, an '81 has the proper heavy wire to the cap.
after many years running these distributors here is what I've found:
-#1 killer is heat. We used to tow heavy and just got in the habit of swapping module/coil before the yearly summer trip.
-I am the cheapest Scot on the planet, but you have to buy the good stuff for these. I have found the Napa/Echlins or delcos to work the longest. Also I get the good cap with brass terminals not aluminium. Use the dielectric grease liberally.

Finally, if your battery is running down fast you have an outside electrical issue clearly. Is it the batt., charge system, a ground or short,? All these will lead to short life on most any sensitive electronic device. I suggest you find the batt drain issue first so you don't keep tossing $$.

[WIDESIDE72]

1. New coil
2. Quality module
3. Proper heat sink compound like Artic Silver

They sell it on Amazon.com

http://www.arcticsilver.com/as5.htm

[WIDESIDE72]

Be sure the engine to cab ground wire is intact and connections are clean; bare metal at connections.

[70c10stepside]

I put in a module today that I know for sure works, not a new one for the time being, but I know it was fine. Out of my buds dizzy he just pulled that was working fine. Getting a new one when I go by the parts store, they said warranty will cover it. And then It went from there. While out I put on different springs that I got last time at summit. Being I knew the curve was way off. I know the distributor is in right. We checked it a billion times. But the first time I hit the switch it sound like two grenades back to back out the carb followed by smoke. Hit the switch again, it turned over for a couple seconds and it back fired out the carb again, much quieter, without me tapping the throttle at all giving it gas. At that point we all looked at each other pretty confused. We next made sure the wires were in the correct firing order, made sure the thing was on true top dead center over and over. Swapped caps/coils, put the mid level springs and then stock springs, not a change. Still back firing out the carb. The fire is right with the compression stroke when we ground the plug on the header as it should. The carb has oily residue inside, a little more then normal from the pcv valve I guess? Same with plugs. Could it be like the silinoid in the distributor itself? Do I have the wrong name for that part? What else could it be?

Motor is hardly a year old. Same with distributor. May have 3k tops on it. The motor is a 350 0014 block, 68 461 327 heads, .030 over, around 11.1 compression, cam is 488/508 lift, duration at 50 is 234/244, lobe separation is 112, still 1.5 stamped rockers, edelbrock torkii 2 intake, holley 750 vs (mathematically to big, I know, but it does very well. Had a 600 vs but couldnt get it right. this one performs great). And the dizzy is just a gm hei that still looks brand new on the inside, with a msd hei replacement cap and rotor.

What is going on?lol Ran amazing before it lost spark this last time. Was playin with vp in it actually, it ran sweet! Plugs had a perfect mixture on them, ran like a million bucks. But now, not so great. I dont know what else to throw at it. Thoughts? Anything counts lol Worked on it trying to resolve from 5:30 to 1030. Taking our time tracing our steps, trying to get it right.

[70c10stepside]

Pic of the motor. Still fresh lol This is annoying!

[70c10stepside]

Anyone?

[magwakeenercew2jh]

Originally Posted by 70c10stepside

Thoughts? Anything counts lol Worked on it trying to resolve from 5:30 to 1030. Taking our time tracing our steps, trying to get it right.

Okay...I'm no expert. But I've had dizzy problems. And, I've had enough electrical issues to be somewhat informed, as well as being a pretty good problem solver....
Okay, that's the disclaimer.

My experience, here, is that the problem owner generally wants to tell the potential problem *solver*, "I've already done that". "So, it can't be *that*."
Not saying YOU are doing that. But, since you asked for "thoughts", it's something to keep in mind.

As for me, with my past issues, I ALWAYS have to go back to the point that everything worked. Obviously, you were having a problem. And you considered it the module.
But, I'd have to ask, then, why did you think you had the potential of having the wires in the incorrect firing order? And, why was there any possibility of you being 180 out
on the dist? Also, why start screwing around with the weights? Or, didn't I understand correctly? Did you have the dizzy completely out of the block?

What's, "playin with vp"? Sorry, I'm ignorant.

Bottom line guess from me, the battery drain has something to do with it. I'd have to go back to "Square One" with decent parts (USA made module), tested (proven) coil,
check for a full 12v at the dizzy.

If you pulled the distributor, 90 percent of the time it doesn't start (all other parts and wiring being equal, that is) it's because you've stabbed it out 180 degrees.

Both a blessing and confusion for me is that it was running well before. So you gotta get at least there so you can sort out what you think is a module problem...or at least
the symptom of a bigger problem is supposed to be a toasted module.

[Lattimer]

If you have spark, and its backfiring out the carb when you try to start it, the dizzy timing is out or the firing order is wrong.

Bad module typically won't spark at all. I recently had an aftermarket Accel module die on me overnight. Worked perfect one day, next day no spark. Module and coil both tested bad with a meter. I bought a complete new dizzy for less then the coil and module from Jegs and it popped right off.

Springs mean nothing at idle and for starting, they just control how fast you advance.


When you stare at a problem too long, you become blinded. Walk away, then start back from scratch. Just because you checked it over and over doesn't mean its right. Been there.

[70c10stepside]

We're about to go get my friends New frame and when we get back we're going to start over. Firing order I know is good, but I'll check if its 180 out again. Always possible. Happens.

And yea, I took it out all the way like an idiot. Normally can get one back in first try, bad day I guess.

I was playing with vp110, race gas. Due to the compression it likes it. I can turn the timing up some and it have the ful power it likes.

And I'm join to charge battery up while we're gone.

Ill get the module while out if I can. I sadly live way to far out :/ lol

[Lattimer]

I just know from experience that every time I am absolutely certain I did everything right....I'm wrong. Happened too many times where I've been frustrated and staring at a problem too long.

[70c10stepside]

It was 180 out lol Dang. But don't mind the frustration. When I pulled it back out I put the bushing in it from the curve kit. Along with the springs that looked good for it. Now it'll fly! I think it can handle more timing but left it alone till I get tape to no for sure. Its smooth as butter, no detenation problems. But till I know I'm not touching it lol Kept up without a problem with my friends 69 camaro that has a built 388, t56 and 373. With its fancy electronics And New aluminum heads, blahblahblah. Where before it wasn't even close. Huge difference! Super fun

[70c10stepside]

Haha Me too! Not the first time. It happens! Have to stay patient and calm