Arg, I've been having some problems with a backfire and I wanted to change the ECM and the ignition module. IM was $40 and they wanted $180 for the computer including the core. When I called they said $89. I called the junkyard too and they don't have one. I would be willing to pay that much if I knew it would fix my problem but I'm not sure. The igntion module did nothing.

 

A ECM is going to do nothing also. If the ECM is bad it will throw a code like 47, 52, or 55. Don't waste your money buying a new one, it will do nothing.

 

Thirdgenresource and Thirdgen Parts at the links at the top of this page both have replacement ECMs for around $50.

 

Junkyard ECMs that will work in your car are as common as dirt. They interchange with practially every other GM car of that vintage. Find a junkyard guy who will look it up for you in the Hollander Interchange manual and go yank it from the "donor" can in his yard.

We just put a junkyard ECM in my brother's 87 T/A and it came from a 4 cylinder Buick Skyhawk, after confirming compatibility with Hollander. You have to swap your chip into it, of course, before you reinstall it in your car but that's no biggie.

PLENTY can go wrong with an ECM and not throw a code. Like bad grounds internal to the ECM. That's what got us this time around. Couldn't idle the car worth a damn. New ECM (along with new ign. module and alternator) and it idles like a champ.