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James, Ford Technician
Category: Ford
Satisfied Customers: 3628
Experience:  Ford Senior Master Tech, Ford gas and diesel expert, ASE Certified
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Workin on a 02 f250 7.3 diesel and it is running really

Customer Question

Workin on a 02 f250 7.3 diesel and it is running really rough. Took it down the road and can't go over 40 with it floored. Put a new pcm and idm n it and still no luck. Any ideas?
Submitted: 1 year ago.
Category: Ford
Expert:  Matt replied 1 year ago.


If you haven't already then consider changing the fuel filter as if this partially blocked this will reduce pressure at the main pump

If both of these are OK then also check the connections to the EGR valve, if either the vacuum pipe of electrical connection are damaged / corroded then the EGR can be on all time which certainly will hurt performance. Its also possible that its a fault with the EGR valve so its worth removing the valve and cleaning it out with brake cleaner, if it looks particularly clogged then replace it.

If this is OK then check the small vacuum lines to the turbo and its connected control solenoid on the bulkhead, any cracks or leaks can give turbo issues and its best to have the boost pressure measured actually measured with a boost gauge to check that the turbo is healthy and that the sensor is reading correctly

If its a variable vane turbo (they’ll be an actuator on the turbo body - but not a wastegate) then check its vacuum pipework as above and check the connections to the diaphragm / solenoid valve

Also worth checking that the glow-plug relay is switching off as they can stick on and leave the glow plugs also on - on some cars this can force it into limp home

Also worth considering adding a bottle of injector cleaner into the tank as a clogged injector nozzle will reduce power and give poor combustion - the next stage on from this is to remove all the injectors and have them ultrasonically cleaned and flow checked

Also check all the high pressure hoses post turbo/s for any split hoses or cracked metal pipes, also check the ends of the intercooler as its not unheard of to pop the end caps off under high boost.

Expert:  Chad Farhat replied 1 year ago.

Hi my name is ***** ***** I will be assisting you today

Customer: replied 1 year ago.
Hey chad I'm Drew. I put a scan tool on it and I try running all 3 test that it lets me. I can only get 2 of 3, the 3rd one seems to take hours so I haven't waited that one out yet. First test is continuous memory test it gives me codes p0603, p1247, and p1316. Second test KOEO gives me codes p0282 and p1293. Just can't seem to wait out the third test KOER cause it take so long. It starts and runs now cause before I got these codes it was only throwing the p0603 code and the idm code and I couldn't get it to start so I bought a new pcm and tried that. That didn't work so I bought a idm now my truck will start but runs rough as hell. Don't know what to do next!
Expert:  James replied 1 year ago.
Hello, if the vehicle is running rough it can be a few things. This vehicle doesn't have an EGR valve. It also has a wastegated turbo so there is no actuator. If the vehicle runs rough all of the time or only when cold? The P1316 is for the IDM internal codes. This usually means the valve cover harnesses are to blame and have come loose.
Customer: replied 1 year ago.
Runs rough all the time
Expert:  James replied 1 year ago.
The p0282 is injector circuit 8 low. The first thing I would do is replace the under valve cover harness from Ford on the driver side. Once that is done retest for injector codes and see if p1316 comes back. If it does next I would perform the same repair on the passenger side. I think that's going to take care of your concern.
Customer: replied 1 year ago.
I hope so
Expert:  James replied 1 year ago.

If you still have a loss of power after repairing the rough running you can always update this question.

Expert:  James replied 1 year ago.

Also please remember to rate my answer so I receive credit for assisting you.