1986 Ford Ranger 2.9 Ignition Control Module Overheating...??

[kxri318]

I'm pretty sure the ignition control module on my truck is overheating on long drives. It's fine for short drives but starts misfiring after 25-30 minutes of straight driving. I drove for about 40 minutes and by the 25-ish minute mark, it started misfiring intermittently. This was happening before, so I took the module off, put a good bit of high quality thermal paste on it (Arctic MX-4), made sure it had good coverage over the whole bottom of the module, and tightened it down pretty good, but it didn't seem to help. I put my hand on the ICM after the 40 minute drive and the plastic casing of the module seemed pretty hot, but not hot enough that I couldn't touch it. I could keep my hand on it fine and not burn my finger. The distributor was hot enough to burn your finger though, which I would think then the ICM would be that hot too since the module is using the distributor as a heat sink. Any ideas on how to make it stop overheating, or if you don't think its the ICM? Sorry if this is the wrong category, wasn't sure if I should put this here or under misc electrical

 

[gaz]

@kxri318 ,
Go-to our "rangerstation.com" tech pages and look up Ignition Module relocation. It involves either purchasing a relocation kit or going to a wrecking/scrap yard and sourcing the relocation system from a Ford Aerostar or like era Ford vehicle, which has moved the ignition module to the passenger side fender apron or behind the passenger side front grill.

I pulled mine from a 3.0l Aerostar. The only thing I had to change was the ignition module; the 3.0l's use a black colored module, the 2.9l required a gray colored ignition module.

 

[gaz]

What we have

 

[gaz]

The fix.

 

[rusty ol ranger]

Have you tried just replacing the module?

The relocation is a good thing though. You can pry pull the parts you need (besides the module itself) from any distributor equipped 92+ ford.

My 97 460 has the module located on the drivers inner fender.

 

[kxri318]

@kxri318 ,
Go-to our "rangerstation.com" tech pages and look up Ignition Module relocation. It involves either purchasing a relocation kit or going to a wrecking/scrap yard and sourcing the relocation system from a Ford Aerostar or like era Ford vehicle, which has moved the ignition module to the passenger side fender apron or behind the passenger side front grill.

I pulled mine from a 3.0l Aerostar. The only thing I had to change was the ignition module; the 3.0l's use a black colored module, the 2.9l required a gray colored ignition module.

No junkyards near me had any Aerostars and only had Mercury Cougars that weren't in the years listed in the Ranger Station article on how to do this. I just grabbed the heatsink from the only 95 F150 in the yard and the connector for the module. Unfortunately I forgot to bring the special thin wall socket tool you need to take the module off of the heatsink, so I had to pay $28 for a module I can't use. I figure I'll just solder on some 16 AWG wires to extend the connectors. There's a good open place to mount it right near the firewall on the driver side fender. I had a question about shielding though, would it be enough to just buy some shielding tape and wrap it around the wires? I also saw that it seems like only the PIP Out, Spout In, and Ignition ground are surrounded in shielding tape on my current wiring harness, all the others are just unshielded wires. Would I shield just those 3 wires in the extension I plan to make, or should I shield them all? Also, would I shield the extension for the 3 wires coming from the spade connectors (Hall Eff. Ground, Hall Eff. Power, PIP Signal) that usually go straight from the module to the distributor?

 

[gaz]

@kxri318 ,

Hi,
I am a big manual reader/manual follower. I did just like the write up suggested and grabbed all the wiring, shielding and the heat sink. All that remained was deciding which suggested method to connect to the distributor.

The way I understand it, all of the shielding is critical since the module is no longer directly connected to the distributor.

 

[kxri318]

@kxri318 ,

Hi,
I am a big manual reader/manual follower. I did just like the write up suggested and grabbed all the wiring, shielding and the heat sink. All that remained was decideding which suggested method to connect to the distributor.

The way I understand it, all of the shielding is critical since the module is no longer directly connected to the distributor.

Alright, thanks for the help. I'll try to get that working in a few days or so.