Just call me Sean

iTrader: (1)

All kinds of crazy stuff can happen with a fried computer. You could compare it to the desktop with a virus.

icer22x

Well, we are replacing the PCM soon so I will post back with results. Hopefully it works so we can finally close this thread... and I can take back the plethora of new parts we bought. Yaaaay...

icer22x

What is the process to replacing the ECM (PCM/EEC microprocessor)? Is it just a simple process of unhooking it and installing the new one?

I can't seem to find any guides for replacing this part.

ymeski56

Pretty much.
Disconnect the battery first. Look behind the driverside kick panel first.

icer22x

Gotcha. We found it today. Ran some more tests from the Haynes manual about the PCM and its wiring harness (Section 4 in the manual) and everything today again pointed towards its failure.

I'm going out of town tomorrow and won't be back until Tuesday. I'll report the results some time around then. Hopefully this fixes the spark AND fuel pump issues. *crosses fingers*

icer22x

Okay, back from my trip with one question...

How in the **** do you get the ECU out? The bottom part of the mount has a little lip on it preventing me from pulling it straight out...
And I cannot raise and pull the ECU because there is something (which I cannot see, probably the metal paneling) preventing me from doing that.

Anyone ever taken a computer out of a 1992?

EDIT: Nevermind... lol We got it out.

gtyjf1

So how did this turn out? Did the new ECU fix it?

I'm having the same problems now and everything I've done is pointing in the same direction.

ymeski56

Well, how'd you do it? Through the firewall?

icer22x

Sorry for not keeping up... I've been busy. But YES. The new ECU fixed it. Now I am having problems with jumpy idle. My truck shut off in traffic the other day... that was fun. Trouble codes are pointing to the EGR valve. The sensor is fine... we tested it... but I think it's the valve. Would that cause the truck to shut off while barely accelerating?

But anyway, we didn't pull the ECU out through the fire wall, but through the kick panel on the drivers side. We took the kick panel out and unbolted the bolts to the ECU from the firewall side. Strange thing is... when we pulled the ECU out with it's harness, the metal harness was all rusted - almost like water had been seeping in. We think that's how the original ECU was fried. So we put silicon around the rubber seal that goes over the ECU and bolts onto the firewall.

And gtyjf1 - Have you tried getting any trouble codes? The way I found out it was my ECU was doing that. I didn't get ANY codes. Even if you disconnect your battery, it should give you an "11" or "111" meaning "all systems pass". But I got nothing... meaning the ECU had been fried. Always try and do trouble codes first. Unfortunately for me, I decided to do this after I had replaced basically the whole ignition system.

But any help on my truck shutting off would be helpful. Thanks!

ymeski56

and what was the code #? did you remove & clean the EGR Valve? Check it's diaphragm?