Ok so I have a 99 24v cummins that goes wide open throttle when the accelerator pedal is touched. Even the slightest touch it goes wide open and won't stop until the key is turned off. We have changed accelerator cable, apps with bracket, have done the apps reset/relearn multiple times, changed cam sensor and we have the vp44 injector pump swapped for a new with no luck. The truck fires up and idles perfect but like I said the slightest touch sets it off and won't stop without turning the key off. It started out going wide open in any gear (auto tranny) but since we have changed all of the following (injector pump, apps, and cable) the truck only goes wide open in gear. In park or neutral you can mess with the pedal all day and it works as it should. But put it in reverse, or any forward gear and it will go wide open?? No smoke when it goes wide open and no oil burn. The only thing I can think of is the ECM?!?
No tuners or programmers on the truck, all factory except 4" straight pipe exhaust and no check engine light, but did have a cam sensor code and we replaced sensor. Oh and when 1st started it lopes like it's got a huge cam but clears only after a couple seconds

 

You pretty much have it narrowed down to the ecm

 

I'm not familiar enough with the trucks to know if the nuetral safety switch is a seperate plug on the transmission or not. That's the next thing I'd look at.

 

Did you ever figure this out? Having same issue.