Thank you in advance to anyone that can help. Last week I was driving my 89 GTA 5.7/auto, and the engine started misfiring and popping and then died. I towed it back home and today I checked it and I have no fire from the coil and no pulse from the injectors. My HEI system has the small distributor with the external coil(coil has been replaced with new MSD ignition coil. I would guess that it could be ECM or HEI module but before I just throw parts at the car, I am seeking help and advise. Again, thank you for any light shed on this.

 

This link has details on how to check the ICM operation

http://easyautodiagnostics.com/gm_ic...n_module_1.php

Quick ICM check
https://www.thirdgen.org/forums/post...560-post2.html

 

OK. Thanks for the info. I checked and had 12v to the pink wire at the ignition coil and went through the test for the ICM. I went ahead and replaced the ICM, ignition cap, coil and rotor why I was in there since I had brand new Delco parts on the shelf anyway. Still no fire out of the ignition coil. Any other ideas?

 

Yes , I've got one ... If your ICM is known good as well as your ignition coil , and you have +12 on the pink , my next test would be to check the resistance ( Ohms ) of the Pickup Coil located at the bottom of the distributor . If this small coil goes defective , both the spark AND injector pulse would disappear . yes , you must remove the dist. to replace it , but you CAN check it , in place , with an Ohm meter ....

 

Looks like I am changing a pick up coil. Thanks for the help.

 

If you worked fully through the link posted ,you would have come to that conclusion (Pg 6 ) without having to replace the other parts

 

UM , I think the gent said he had the brand new parts already on hand , so I really see no harm nor foul if he wanted to try them first . Now that the problem has been diagnosed to the pickup coil , I have one more small piece of helpful info for the OP . When you have the distributor apart to replace the pickup coil , hop on over to your nearest "Radio Shack" and pick up a small tube of their best "Thermal Compound" and use that under the ICM while reassembling the distributor . The stuff that comes with the ICMs is a joke , and I suspect is the prime reason why so many folks have ICM troubles . I speak from an electronics background and believe me , a cool semiconductor (the ICM) is a HAPPY semiconductor . Just make sure to clean ALL of the old stuff off first , right down to clean bare metal , and use only enough to squish out about 1/16 of an inch from under the tightened down ICM .

I have NEVER had a failure of a new ICM mounted with the superior thermal compound available in electronic hobbyist shops like the 'Shack ....

Best of luck and report back when ya got a happy running car