The truck is a 1998, 5.4L 24V Cummins, Ram 3500. A couple of months ago I lost the lift pump, which also took out the fuel injection pump. Truck has 125K miles on it. With both replaced, the truck ran good for about two months. Now, when the truck sits for a few hours, the engine cranks for about 5 to 7 seconds before it starts. It sounds like the engine isn't getting any fuel. So having read about the lift pump previously, I decided to try an experiment. I clicked int he starter for a split second, without starting, and left the key in the 'on' position. This is supposed to trick the lift pump to run for 20 seconds. I could hear the lift pump running, and after it ran for 10 seconds, I'd hit the starter again - engine will start instantly.

Any idea of what this might be. Lift pump seems to be running, Is there a check valve of some sort that might be letting the fuel drain back?

Any ideas would be appreciated. The rebuilt injection pump did come with new electronics. The lift pump I believe is a Carter.

thanks

 

Air getting into the lines somewhere.

I'm not as familiar with the 24 valves but on the 12 valves it's somewhat common for the fuel return lines to develop cracks that will allow air to enter, but they don't leak fuel.

So I'd start by looking for any fuel leaks, then look for old looking rubber hoses and replace those.

And it's a 5.9 liter, not 5.4...