My 99 cummins with a six speed is ******* out on me while driving. It almost feels like a brake dragging but that is not the case here. you can hear the motor idle drop and feel the great loss of power. I am running with a new vp44, fass ddrp lift pump, new 50hp bosch injectors and a new tps. Also new air and fuel filters. Only does this around 2000 rpms and if you punch it while this is going on the truck will accelerate like normal.

Is it air in lines or a bad vp44? There is no check engine light coming on either!

Help

 

get rid of the ddrp and get a better pump also get a set of gauges so you know what your fuel pressure is. anything else done to the truck now programmer or anything?

 

No, thats all. I just put that pump in, however the truck was doing this before I replaced it. It came highly recomended from gomers diesel.

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Could this just be air trapped in the lines?

 

01quadcab is right on with what he said... try bleeding it for the hell of it, you got nothing to lose by trying, but you really NEED to know your fuel pressure. That brings up another perk of having a strong pusher pump, by just bumping the starter the system will prime 9 out of 10 times you don't need to crack lines.