The Stovebolt Site Forums The Shop Area Engine Shop A couple of questions about HEI

I put a GM HEI distributor on my '57 235 4 or 5 years ago. I think it's from a late 70's or early 80's truck. I found a "how-to" somewhere that described how to make the necessary modifications by grinding off a stop and replacing with a locking collar. I've probably only driven the truck between 100 and 200 miles but it's worked great until yesterday. I was going for a short drive when the engine died about a half mile from home. It quit just like you turned the key off. It's getting no fire to the plugs. QUESTION #1: Before I start tearing into this I would like to find those instructions again to make sure I've got everything installed correctly. I searched the net but didn't find anything. Seems everything is about the aftermarket HEI kits now. Can someone point me to a tech tip or how to article for this change using a GM HEI distributor? QUESTION #2: Is it possible that something has slipped just enough that the distributor is not engaging the drive and not rotating? That's the first thing I want to check when I have time to work on this again. I've already verified that the relay is working and I'm getting 12V to the distributor. Thanks for any help.

Jeff

It sounds to me like the ignition module went bad. When they go bad it is just like you turned the key off. Google "HEI ignition module test" and give it a try.

I neglected to mention that the first thing I did was replace the ignition module but it's always possible that the new one is bad too. I'll try the test next. Thanks.

EDIT: Actually, I replaced the coil, not the module. Sorry, ignorance on my part. I'll do more testing to isolate the problem. Thanks again.

I carry an extra module in the glove box just for this reason. I have had HEI's in everything I drive, and they do go bad every now and then. Used GM units are better then new aftermarket ones most of the time, but if thats all you can get, you do what you have to do. When they quit, they are done!

Shouldn't take much to release the cap and watch for rotation while cranking.

I tried to remove the module last night. This is what I ran into:
http://s305.photobucket.com/user/jfnar/media/57%20chevy%203800/IMG_03701_zps1trtvvsi.jpg.html

The screw on the right can be removed with a 1/4" socket. The one on the left is a one-way security screw. The kind where the screwdriver cams out when you try to remove it. Any suggestions for removing it.

Thanks.

Track down the person responsible for setting up that distributor and pound the puddin' out of him. Unbelievable!
You can cut a slot with a Dremmel and remove with a flat blade screw driver. Then you will need to get all of the metal shavings out of the distributor.
Carl

The red sticker says your going to void your warranty.

Back in the 80's a few Buicks would have a both a bad pickup coil and HEI module.

If I remember the pu coil would go bad and fry the HEI module.
Jeffrey

Something tells me, that the warranty on a HEI from the late 70's or early 80's is not an issue. The good news is the parts are GM and not after market. So the book for the car or truck it came from will still be useful. The local FLAPS will have the bits you need. Slot the screw and throw at the guy who installed it. local FLAPS will have the screw too. The test procedure from the car/model will still work. Generic but useful, even covers some trouble shooting of components: http://www.autozone.com/repairguide...Ignition-HEI-System/_/P-0900c15280051338
Should work for you.

Got the screw slotted with a die grinder and easily removed the screw. Put in a new module, reassembled with new phillips head screws and it fired right up. I'll get another module to keep in the toolbox. Should be able to change it out with nothing but screwdrivers in an emergency. Thanks for your help.