Occasionally the engine will not respond to the accelerator's request for more fuel between 45 and 60 miles an hour.

For instance, I am driving at about 55 in OD. I can feel the accelerator pedal start to go toward the floor but the engine does not respond. The pedal will continue all the way to the floor eventually causing the truck to shift into 3rd and then respond to the accelerator in a normal fashion. If I feel the pedal going to the floor with no response, I can quickly shift off the OD and then release the accelerator pedal and then press the pedal in order to pick up speed. The truck will respond normally after I do this.

This happens either in OD or in 3rd. This will happen with the cruise on or off. This happens ONLY when I am deadheading empty. It NEVER happens when I am towing a trailer.

This happens infrequently but seems to be happening more and more as I let the problem continue.

The shop checked the codes and determined that the TPS and the VSS both were putting out failed codes. The VSS was replaced. The quick-connect for the TPS was taken apart and sprayed with a WD-40 type fluid specific for automotive application.

The problem is continuing after that repair.

The TPS was replaced at 117,000 in October of 2003.

Any suggestions? What should I do next to resolve this problem? Do I dare take the TPS apart and spray it with WD-40?

 

check cummins for wiring diagram be very forceful in getting for they probably have it if not previous year or years probably applicable I suspect loss of idle validation circuit use ohm meter to measure correct pin circuit (or proper pin out)

 

It turned out to be a injection pump. Cost $1500 and some change. Anybody want to buy a truck?

 

You can do better than that for an injection pump, 1500 is a bit pricey, They are not that difficult to change. You have great resources at your disposal on this site, use then and save yourself some $$$$$$$

 

twhite JUST RUINED MY DAY! I am having EXACTLY the same problem! Just replaced the LP, wasn't totally dead, but was missing at high rpm.

Cummins mech in Fargo said I have a restricted fuel intake (8" hg). I pulled the fuel tank, it was clean. Blew out intake line with air compressor just in case. Haynes manual said special tools are needed to check vacuum pressure in intake line.

Replacing injection pump easy? Cheaper place to buy than Cummins dealer?

I have a fuel pressure gauge on order.

By the way, this message board already saved me $$$, I went to a Dodge dealer, he said LP ok, LP listed at around $400, Cummins dealer $143.