01 dodge cummins surging problem
 

Howdy, Very new to this but I hope you guys can help me out. I have a 01 dodge with a cummins that surges at about 60-70mph. Seems to go away if I floor it most of the time. Happens more so on damp days,both summer and winter. It has the Banks power pack on it. I have disconnected this and the problem is still there. Has a new TPS sensor and FASS fuel pump. That did nothing. Transmission is a built up Goerends tranny ,no problems shifting or holding gears. Batteries are new,cables are tight,Ive checked the grounds that I know of. It isnt throwing any codes, and the problem is driving me crazy!:argh: Any Ideas?

Mine did that also and it was a dirty fuel filter and weak lift pump.

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Welcome to Diesel Bombers!! :tu:

:howdy::hi:
Could well be an injector issue, or worse yet a VP44 issue. Hard to tell without hooking it up to a DRBIII though...
Have you cleaned the MAP and IAT sensors? They can do some funky stuff when they start to go bad; a bit of a shot in the dark though...
What is your fuel pressure?

The fuel pressure is at 10-15 psi idling or under a load. The lift pump is brand new and the fuel filter is new as well. The truck has been doing this for 5 years intermittently. The Banks system makes the problem more noticeable,but the problem is there hooked up or not.:humm:

Do you know if the VP44 is the original, or has it been replaced?? Also, how many miles on the truck.

Any fueling box will aggravate any current issues. Many have laid blame on the box, but it's rarely the problem, it just makes things more pronounced. It could be any number of issues, and most are difficult and time consuming to troubleshoot unfortunately. Hope for your sake it's not the VP44... :scare2:

More times than not, if the VP44 went or is going bad, it'll set codes. Have it scanned and let us know if any codes are present.

The truck has 210,000 on it. The turbo has worked just fine,spools up good and hits about 35 psi boost. I just checked the codes and there are none. It seems almost like someone is shutting the truck off and back on when it happens. Its pretty randomn, but happens more when its damp out. Electrical maybe? I am an ASE certed mechanic for cars and light trucks,but dont know a lot about diesels. I have 4 Dodges with Cummins thou,and they have been great! This problem is stumping me big time! 2 repair shops said it was the tps,so I finally put one in even thou mine swept tested good,and 500$ later its as good as it was before. Ground issue maybe? I cleaned the battery ground to the chassis and block,is there something Im missing?

Have you tried reading TPS voltage @ the PCM? If the ECM is on its way out, the PCM Voltage reading for the TPS could fluctuate or differ from ECM TPS voltage.

TPS voltage is at 4.5 volts at the PCM. Ive heard of cutting the black wire at the tps and adding a new ground. What do you think? The Injection pump was replaced about 2 years ago due to a bad lift pump. The problem was there before and after the new pump.