01 p-pumped 24v won't hold prime
 

so first off this is not my truck and it's in another state. It's my brothers truck and he had the p-pump conversion done by a local cummins guy. They put a 180hp p-pump on it and it has a fads 150 titanium lift pump. He has to crack the fuel filter to prime the fuel system and it starts fine. After shutting the truck off the fuel pressure drops to 0 rapidly. Goes to restart and lift pump kicks on but doesn't pump fuel. No external leaks and no air in the system that we can tell. It has a stiffer spring in the lift pump. Anyone have this issue or know why it would lose all pressure so rapidly?

Have you checked the fuel return lines?

That's what I had him check first. I don't know how they plumbed the pump in. He says everything is fine on the return and no external fuel leaks. It's odd that it will hold pressure once primed though. I would think if a return valve was stuck or dirty it wouldn't hold pressure at all. The p-pump is a reman

Did he get the bolt on the back of the head? Have him park with his nose down hill and see what that does. If he tightened it down it wouldn't let air into the system.