Hello everyone, I have 96 7.3 PSD. 4 days ago it started running rough. Let it idel for a few min. and it ran fine the restof the day. Next day it did the same thing. The next day it ran fine all day. Yesterday it started fine then about 30 seconds later it started running rough again and would not clear up. Sounds like it is running on 4 cylinders no power and check engine light is on when it runs rough. Drove it to local shop where they hooked it to the computer, tried 3 times and would not read it. Took it to auto zone and theirs said no codes. A couple of times on the way home when I would press the clutch and let off fuel pedel it would clear up for about 2 miles and start doing it again. I have read a lot of posts here and wondering if CMP is going bad or something else. Truck has 91,700 miles. Would appreciate any and all help.

 

Sounds like a fuel filter. Otherwise might be the injectors. I would ty a new fuel filter, and a fresh tank of diesel 1 with soem powerservice injector cleaner in it.

 

Thanks for reply. It has only been about 2 months since oil, oil filter, fuel filter, air filter change. After doing a little more reading I started it this morning, let it run for about 2 minutes. Felt the manifold on right side, it was warm, felt the left side it was still cold. Went straight dealer and bought 2 wiring harness. When I got home and took the valve cover off the front harness plug was melted into the gasket plug. Dealer closed at 2:00, spent 3 hours digging melted plug out. Now it is running great again. Thanks to everyone here for the post's and replies

 

They plugged the computer into the terminal under the hood right? On PSD's this is not used. It must be connected to computer under the dash near the center.

Wish I had read this sooner. I've had the same problem. The melted harness can come from moisture in the plug ins. Hope you hit it with a water displacement spray.