I have a 2004 Dodge Duelley with a 5.9 Ho in it.. the other day I stopped at a red light. When I pushed the petal to continue it would not get up to over 40mph. I stopped and turned the engine off a...
Depending on build date, if the Cummins under your hood is 3rd generation, the throttle is 'drive by wire'. As suggested above, could be the throttle position sensor or an issue with the ECM. A shop with the appropriate diagnostic equipment should be able to connect to the truck and track it down for you.