I have a 2000 F250 4x4 super cab with a 7.3 diesel and automatic transmission that starts and initially runs fine. Yesterday, after driving for about 30 miles at highway speeds, the engine would slow to an idle, and after letting up on the throttle, would then drive normally for another mile or so and then repeat itself. I discovered that it was possible to put the transmission in neutral, at which point the engine speed would increase to about 1800 rpm for several seconds before falling to an idle, where upon I would put it back in drive and continue on until it did the same thing all over again. The engine runs strong when not trying to idle. After arriving at my destination, I changed out the fuel filter and drove it for about 10 miles before it started doing the same thing all over again. The outside air temperature was pretty hot (around 95-100 degrees), in case this is a heat related issue, although the engine operating temperatures were normal, i.e. around 180 degrees. Any ideas out there? I appreciate any input...

 

Sounds like a possible cps issue.(or maybe a tps/ivs)

Any way you can scan for codes?

Also, you might post this in the 7.3 section.You'll get more hits there.

 

Ok, scanned the computer and got a pending code P0221, which is Throttle/pedal position /switch B circuit range/performance problem (according to the code reader).

I will look up code P0221 as well as try to find out where the TPS is located.

Thanks for the fast reply.

 

BTW, is it possible to shove this thread over to the 7.3 section, or is it necessary to just start over agin?

 

Well since you got it figured out,no need to move.

The tps is mounted on the accelerator pedal.