2.3L ('83-'97) Truck Frying Ignition Control Modules

[tinoracha]

I've got a 92 ranger that seems like the ICM is repeatedly going bad. A few months ago I was suffering from low power, loud idle that was inconsistent, and a weird read out on my tachometer. After chasing my tail I ended up replacing the ICM and the issues went away, power was up and the tach was giving an accurate reading. Now, 4 ish months later these issues are slowly cropping up again. Is there a component upstream from the ICM that could be cooking it? Or is it more likely an issue with the wiring?

I've heard in the past that auto parts stores used to be able to test the ICM but it doesn't seem like thats the case anymore.

Thanks for the help!

 

[tinoracha]

View attachment 126248
Here is the closest I can find to a wiring diagram for the DIS

 

[RobbieD]

Excess heat is bad about killing those.

Are you cleaning the mounting surfaces and putting a heat-sink compound on the ICM before mounting it?

The factory manual that you pictured the page from, a couple of pages after the diagram, notes to use "Silicone Dielectric Compound" on back of the ICM before installing it.

The compound helps transfer heat out of the ICM.

 

[scotts90ranger]

In all the years I've had my '90 I've only had an issue with the crank sensor once and replaced it. That's not to say I haven't had DIS module issues but as it turns out they were completely self inflicted... when I went turbo and kept the DIS I initially put it on a 1/8" aluminum plate about 6" by 12" with heat sink compound and just zip tied it where it fit (janky as heck). At that time every now and then it would stall after running for a few minutes then start right back up after like a minute and be fine for hours... As it turns out the 3 bolts it's originally bolted down with are used for a ground for the module and it's important, also for whatever reason you don't want to ground the 4th hole, I heard but don't remember... for a couple years I simply ran with an alligator clip jumper from the plate to a good ground and it worked...

So long story short I agree with Robbie about cleaning the face and using compound and making sure the 3 screws have a good ground...