Having the typical ignition issues that I've read so much about, but I'd like to know if there is anything I need to check aside from voltage to the ICM that would cause a new one to fail. I replaced the old one with an ICM from AutoZone that was not a Motorcraft part, and I feel that based on what I have seen on here that is probably my issue. However, I'd like to be safe and check what I can to make sure I don't burn out a 160-dollar part.

1994 F-250
4.9L with the ICM on the Fender and Black

P.s. what is this grease for electronics I keep hearing about with these as well?

 

It isn't grease.

It's Thermal Compound, or Heat Transfer Paste. People call it different things. It's the same stuff that you use on heatsinks in computers, for things like MOSFETs and CPU Coolers.

The garbage that comes in the little packet with the ICM's from most sources is generally Dielectric Grease (I've also seen RTV, Lithium Grease, Thread Sealer, and who the hell knows what else.), which does basically exactly the opposite of what a Heat Transfer Paste does.

 

I just picked up some Acrtic MX-4 for my icm. Seems to have good reviews… I’m not an expert on thermal paste.

 

It'll work fine, and better than anything that might come with a new module.

 

I just joined today and I hope someone has the answer to my ICM issue posted in another thread.
To answer your question I have read coil insulation can break down and that could cause a problem with the ICM.

Since my recently replaced ICM failed I choose to replace the 25 year old coil first.

Now the reason my ICM failed could be related to a recent short in the engine power box. As I was getting my truck ready for smog I saw a wire going into the box. The wire I knew was from a camper shell light a previous owner installed. The bare wire was stabbed directly into one leg of a 50 amp fuse.
I pulled the fuse and wire and reinstalled the fuse. The truck was started and going on the road started to misfire and stall. This happened repeatedly until I was able to get back in the driveway. Checking for pulled wires or vacuum lines nothing was out of place. Had to be related to the fuse. I pulled the fuse again and cleaned the legs and degreased. After that the truck ran normally again. However it may have caused an issue with the ICM which failed within 100 miles. Actually the symptoms were exactly the same as a failing ICM even though it was a poor connection at the fuse. That's my story.

Bruce

 

where does it go? inside ?

 

Clean both mounting surfaces with de greaser and then rubbing alcohol. Apply a coat of the grease on back of module and re mount

 

Between the Mounting pad on the Distributor and the metal surface on the back of the module (Or the fender mounted heatsink, and the metal surface of the module, if you've got a later truck).

You don't need a lot, on a surface this size, a few small pea sized dabs of down the center of the long axis generally works best, the layer of schmoo is *supposed* to be thin, it's basically there to "fill in" all of the surface imperfections on both surfaces, and provide good heat transfer between the module and the heat sink surface.