heinzboz

I have a 99 cummins in and F800 truck. I recently had a new IP put in, and I'm assuming they would have replaced the lift pump as well, but who knows? Anyway, the problem it just recently started having is when I have to stop on an uphill incline. The engine will cut out and run rough and the engine warn light will come on and then go off. The idle kind of jumps around and revs up and then almost dies. The weird thing is it really only seems to do it in the morning when the engine is cold. Would it possibly be a weak lift pump not keeping the filter canister full? I don't have a pressure gage right now, but I do have one of those low pressure warning lights I could install. Anyway, I'm just looking for suggestions for where to start looking. I cant get any codes.

Thanks

rebal

Is it a vp pump? or a p pump? hook up a pressure gauge to see if its low fuel psi also could be cam sensor

heinzboz

its a vp pump. I dont have a pressure gauge right now. Would a cam sensor be affected by stopping on an incline?

rebal

If its loose but cold out side can do it too I would check all your wire connections too when things warm up things change

thumper549

I am having the same problem

thumper549

OK for me so far..I hot wired the L.P. I see pressure all the time, now I just feel it miss....so has not stalled while it is Hot wired...so, the problem I believe is a "open" to the ECM...I am researching where the hot wire can be spliced into that.