thefullmonte

Greetings all. Been lurking on here for awhile and have always been able to find the answers I needed, but I'm stumped. I recently picked up a 96 f150 4X4 with the 5.8. Truck is in really good condition for it's age. Just shy of 175000. I've been doing a bit of tuning up here and there as time and $$ allows.
Started with all the normal goodies. Cap rotor plugs air and fuel filters.

The truck had a hesitation when I bought it. Still driveable, but annoying. And was throwing codes P1351 and P1359 and I can't remember the one for the EGR sensor. Anyway, The 2 codes pointed to the gray ICM that should have been black. So I replaced the ICM and also replaced the EGR sensor, IAC valve and TPS as I was going to do that anyway. So truck is running perfect. No hesitation, no codes. Sweet, I love my truck.

This morning I come out of a store and go to start it and it sounds like it is running on 2 cylinders shaking like crazy and basically dies. I could get it to start intermittently, but i wouldn't move under it's own power. After a lot of aggravation I grab the old parts and head back to the truck. I check the codes again and it's only throwing a P1351 ~With the engine running the PCM detected a fault in the IDM circuit from the distributor. I plug the gray ICM back in and the truck runs. I'm thinking that's odd so I head to NAPA and pick up a new black one thinking somehow the Motorcraft one fried. Plug in the new black one and it does the exact same thing as the Motorcraft unit. Will not run. Plug the gray one in and it runs again. Not great but I make it home. The gray ICM is throwing the 2 codes again. P1351 and P1359. Indicating it's not right.

It is raining outside, but it's not as though I haven't driven this truck in the rain for hundreds of miles already. Any thoughts? Is there a sensor in the distributor I need to be looking at? PIP? As that's kinda where my brain is going right now. Thanks in advance for any light you might shed on this issue.

Steve83

Click this thumbnail (or the link below if necessary), read the WHOLE caption (it's long), put the correct ICM in, and then keep the procedure & tools in the truck so you can diagnose it next time the symptom is present (which sounds like IMMEDIATELY). Putting the wrong part in tells you almost nothing, but it does suggest the only fault is in the ignition system.


(phone app link)

thefullmonte

Thank you so much for this. A little overwhelming, but I'll plug away at it. I did end up replacing the PIP yesterday before I saw your reply. Truck ran good for about 2 minutes and then started doing the death rattle again. I noticed that trying to give it gas does little to nothing. No change in RPM. It did throw a different code this time. P0385 Crankshaft position sensor (misfire sensor) b circuit misfire detected. Or something along those lines. I don't remember the exact terminology.

thefullmonte

Time will tell, but truck is idling perfectly for now. Traced the issue to the coil. Tested it and it was BAD! 20/20 hindsight I should have tested that sooner, but now I have piece of mind that most ignition items are new.

Steve83

I'd worry about that. In my experience, original parts (even 25-year-old ones) are MUCH more reliable than most new ones (even some MotorCraft).