WE have a F650 Long Steak Bed. I know this might not be the right place to post, but closest i could find. We recentaly replaced the computer in her, bc she was bogging down really bad and the ford tech sug thats was the problem after checking her out. That fixed the problem for a few, and back to same thing. We did some more studing and had a guy tell us that the alt could be going bad causeing her to running bad. Checked that out and had a bad dieod. Fix that problem. Now shes still doing the same thing.... It is a stick, and the are no engine lights on as well.. Any sug on what could be going on? We are now back to square one. We were told that we might have to get the computer flashed to mathc up with the truck. But we pluged it in and it ran fine fore a few. Could this be the problem, we didnt get the computer flashed???? thanks for all the help....

2001 F250 Cummins ISB/5.9L Eng Ser# 5684730

 

In your description you say you have a 2001 F250 with a cummins? Im going to assume you meant the F650 with a cummins ISB 5.9, I believe this truck has the vp44 injection pump on the left front side of the engine (drivers side). This engine has a fuel lift pump that is mounted on the same side of the block towards the back. I would recommend you check your filters and fuel pressure and make sure there is no air in your fuel system. Sometimes the lift pump will start going bad but not enough to throw out a code. Same goes for the injection pump, usually you get symptoms like smoke, or even symptoms like a trans concern where you accelerate full throttle and the truck only goes max 5-10mph. are you having these concerns?

 

IT DID THAT before we replaced the computwr on the right side of the motor. It runs not as bad now that we changed the alt. All the filters have been chanhed refently but are there any filrer that i would of not t know of lol.

 

check your fuel tank, make sure your fuel gauge isnt lying to you. Then if your fuel filter is good, fuel pressure is good, and there is no air in the system, it sounds like you might have a pump issue. When I replace the vp44 pump, I replace the lift pump together with it.