ive replaced the ball valve fitting at the vp and still does it,seems to be worse when the truck is paked with the front of the truck pointing up hill but seems to do it more now on level also, anyone have this problem any suggestions?

 

When mine did this I had it towed to Cummins and they found a bad ground on the lift pump. When I would use the bumpin the starter method to try to prime it as soon as the pump shut off you could hear the fuel run back into the tank.

 

I have posted at GREAT length about this before, so if you search the terms "los* prime fuel" and my username you can find those postings.

In short, your fuel system is a loop, and a leak anywhere can cause a loss of prime. My problem was a leak on the return side of the fuel system. I also had tank pressurization, which was caused by an injector that wasn't seated properly.

Jlh

 

Here's the thread I posted in....


https://www.dieseltruckresource.com/...uel#post629189

 

boy hohn that thread brings back some BAD memories laying under my truck

Jason

 

my leak on that was 5 of the 6 injector lines going from the IP to the head.