97 F250 superduty 7.3 Truck OD light was blinking and hard shifting started occurring a few weeks back. This happened last year the day after i bought the truck, took it to Ford Dealership and they said there was a burned wire behind fuse panel. Cant recall if it was #8 or #18. But fixing the wires caused the truck to run and shift perfectly. Fast fwd to the present time... OD light came on and same shift issue began once again. Dealership was super busy so they put me of for few weeks. Went to start truck and it wouldn't crank ... finally got it started and when idle it wanted to stall out, when mashed accelerator it slowly starts to idle up. Put it in drive and it was shaking fiercely misfiring and would not idle up at all, accelerator to the floor and it would not go past about 1300 rpm. Finally got to dealership and they said bad cam sensor was the first problem, they replaced it. Then called me and told me the truck wasn't firing on 3 cylinders and couldn't get a reading on those three injectors/cylinders so by the time they check all that out their advise is to get a new engine or they couldn't help me further. They parked it out back and I picked it up 6 hours later.... IT RAN PERFECTLY all the way home. shifted fine, everything was flawless, no misfiring, smooth riding. I fired it up the next day and drive 15 miles or so ... ran smooth and just perfect. I let it sit for the weekend and when fired it back up it was back on the misfiring on 3 cylinders. Someone please tell me what can cause this issue and how do I fix it? Ford dealer wouldn't even look at the wiring that they repaired last time, they were confident that wiring had no part in it. Which blows my mind that they wouldn't even look at it after that was my first request. I need some help, I use this truck for work and I can't afford to let it sit in the yard or be forced to sell it for 1/4 of it's value just b/c it runs so bad.
Any help would be greatly appreciated!

 

The shifting issue sounds like typical PSOM issues in the cluster. I had it in my 96 F250, and currently battling the same thing in my 96 E350 PSD. I rebuilt the PSOM in the van already, but used a polar capacitor where a bipolar one should have gone, and it's better than it was, but starting to act up again. As for the engine, sure sounds like classic UVCH to me. Wiggle the connections on each side with the truck running and see if it starts gettin shitty on you