Our 95 F250 7.3 PSD (115,000 Miles) has been running like a "Freight Train", jerking and chugging with loss of power. No check engine light. If we take OverDrive off it helps a little. If you floor it it will level out somewhat but chug/jerk is there in the background. There was a slight wiring burn smell about 1000 miles ago, just after this started and the poor preformance has gotten increasingly worse. Also getting about 8mpg which is low it seems.
It has new Glow Plugs, Transmission, Brakes. We did our glow plugs ourselfs a year ago. Oil is changed every 3,000 and gas filter was changed 1,000 mi ago.
Searching the forums I find ref to burnt wiring harness, bad valve among others. I'm leaning toward the harness.
Please tell me this is something simple that we can handle and is not going to break our already "BROKE" bank.
As I have always said, I am just the writer, hubby is asking the questions.

 

I had a 95 that that's happened to twice and both times it was glow plug that went out and caused harness to melt. check plug ins on valve cover, you'll probrably be able to see if it's burnt...Rodney

 

Sounds alot like mine (1999) did when I had two bad injectors.....god awful ride but replaced the two injectors and smooth as glass...

 

We had a friend run his scanner on it last night and got the CODE PO472.

 

P0472 is Exhaust Pressure Sensor Low. I'm not sure how that equates to your problem though. I'm still leaning towards a burnt injector harness. Hopefully someone else will chime in with some helpful thoughts...

Max

 

We took our "Freight Train" into the local shop and had the following done after he ran the codes.
Replaced EBP Sensor
Cyl Balance Test
Cyl 4 Replaced Valve Cover Gaskets w/loom (wiring harness was burned)
Cyl 5 Inner Loom Replace Eng Wiring Loom
Replace Valve Cover Gasket w/loom
Replace Eng Wiring loom

After all of this we still have low compression on Cyl 4 and 5. It is still running and sounding like a freight train. A little smoother but not much.
His only suggestion was we take it to the Ford dealer as his Diag computer is running no bad codes. YIKES

THIS PART IS IMPORTANT:
We had a new transmission put in in April. Bigger/better. This started about 1000 miles later.
When we take the Overdrive OFF it runs smoother

PLEASE Help

Thanks Guys

 

did you run a compression test that tells #4 and #5 are low and if so the reason it runs better out of overdrive is because it's not making enough power ,it's lugging the engine, in 3'rd gear rpm's are higher. if low compression, could be rings or valves,either probrably not cheap fix....

 

have not done the compression check yet. That is a trip to the dealer. Is there any chance it could be those two injectors or possibly the O rings on those two? Would rather start cheap and go high if possible.
The tech said there were two glow plugs not making good contact when he got into it.
What is the danger of running it in this condition before it totally goes up the river, with a paddle, without a canoe??????

 

The problem I had with mine was fixed with changing glow plugs and wiring harnesses, I didn't have to any further you mat want to post your questions with a new post and see if anyone else had that problem. sorry I couldn't be of more help.........