I just got back from a 1600 mile trip back to my house and most of the time my fuel pressure gauge showed zero psi. My rail pressure seemed normal the whole time. The truck ran normally even when giving it alot of throttle merging onto the freeway. Is it possible to have a failed lift pump and have the CP3 pull enough fuel for this scenario over this many miles? Or is it more likely air in the sender or something like that? I have a Quad Commander and the fuel pressure kit for it where the sender is mounted on the CP3.

Thanks for any ideas!

 

There is a problem with the sensors for the commander's. I have the exact same problem on my truck also. I talked to Quadzilla and they are trying to figure out what to do about replacing the sensor with a better unit. Do some searching here. There are a few posts on it.

 

The 2nd gen VP44 trucks would run fine if the LP died but eventually the VP44 would die because of it. The CP3 trucks are designed to stop running if the LP dies. The truck would run fine (Duramaxs run a CP3 w/ no LP) but the CP3 cannot pull fuel through a LP that is not running...

 

Thanks for the replies! I'll get in touch with Quadzilla and see about getting a new sender. Its good to know that the truck stops if the lift pump stops, at least I know it isnt completely kaput.