I have a 1992 F25 with a 5.0 and E4OD transmission. I've posted several threads about a cold start problem. It won't start good when cold. If it's 65 degrees outside it'll start fine and run like a top. But in this 30 degree and lower, well it runs like it's only using 3 cylinders out of 8. But once it warms up It's fine. But during warm up It'll have a few misses here and there. Eventually it's ok and drives fine. I'm doing process of elimination with it. I'm now wondering if the PIP sensor is bad. (PIP, STATOR, Hall Effect whatever you wanna call it haha) My question is this though, if it's bad, wouldn't it run bad always instead of just when cold? And I also heard that it runs the Tachometer. If It does would the tach not work right? Because it appears to be working absolutely fine. OH! And another important thing.. I grew an idea. I read about the ignition having a "Start Mode" wire on the ignition module (I got the fender mount one and it's gray in color)so what i did was this.. I had it running but it was idling very choppy. So before it warmed up I UNHOOKED (don't freak thinking I killed my starter lol) the starter relay and held the ignition in Start. It ran fine when I did this but once it goes back to run it acts up (until it warms up of course) I heard that when in start it ignores PCM timing commands. Doesn't the PIP tell the PCM what to tell the ICM? Or what else would have a "Start Mode" type feature. NOW THE WORK DONE-----


I checked for codes and all I got was the 111 code. At one point I had a trans code about a EPC (i think) circut open. I check and the plug was dirty. I cleaned it, code is gone and my trans doesn't slam so YAY!! (btw I changed the MLP sensor and it's plug. There wasn't enough grease on the plug)

NEW ECT sensor (I originally thought that'd be the problem but no. I even tested both sensors any way)
Fuel pressure was absolutely FINE! All new fuel parts as well. I'm always told to check fuel pressure but most think I'm lying!!

New plugs, cap, rotor, wires, Coil, O2 sensor, exhaust, Throttle Position Sensor, EGR is fine, Cleaned the intake out, and probably more but I can't remember. Could it be the PIP or do you think It's something else? I'm very poor (who isn't anymore aye?) so I can't throw much money in it. If I could, I'd have a carbed classic Chevy haha.

 

It sounds like you and Proweld are having similar but isolated problems. I was reading the checks for the remote-mounted TFI/ICM in my haynes manual and compared to what you described.

1 question I have is concerning high resistance and grounding issues. I know you must think I'm crazy for thinking this up, but I'm not sure if you have checked for this or not. I would check all grounds and check the resistance in the PIP circuit.

If you need further directions on the ICM, let me know. I have them right here.

 

I wouldn't doubt that could be an issue. I have a knock off repair manual which doesn't give the greatest info and I'm not too sure how to check for ground/resistance issues due to lack of books info. ha, this book told me that my trans took nearly 5 gallons of fluid haha. Any info would be much appreciated!

 

I also forgot to mention that I checked the base timing with the spout off and it was a 10 degrees like it said it should be. I bumped it up to 12 and there isn't a difference. It seems like it has more power while driving though. Like I said, once it warms up it runs great and drives great!

 

Sounds like a bad ICM (TFI module) to me.