4.108 perkins

[Rbrucek]

My engine is not holding prime. If it sits for any more than two days it will not start. Any ideas?

[sailormed]

What have you tried already?

[Rbrucek]

We have just bled the lines.

[oldtom]

Originally Posted by Rbrucek

We have just bled the lines.

check your fuel lines from lift pump to the injection pump if ok. check valves in the fuel lift pump, there are two inlet & out let, they wear.

[Lepke]

The valves in the lift pump act as check valves allowing fuel to only move toward the injector pump. Dirt in the fuel can cause them to wear or embed on the valve surfaces, either allowing the fuel to flow backwards.

If you install a 12v inline pump, it makes it easier to bleed and change filters. Installation can be before or after the lift pump. (About $20 on ebay) It also give you two more "check valves". Either pump will draw or push fuel thru the other. 12v doesn't need to be on when running. Or you can use the 12v all the time. If adding a 12v pump solves the problem, then the original lift pump valves were the problem.
But, for the fuel to drain back from the injector pump, there needs to be an air leak somewhere. It could be the bleeding seats are damaged.

[Rbrucek]

Thanks ok look at that. I have a 12v pump in there.

[Rbrucek]

If the engine got really hot because we didn’t relish the raw water impeller went bad can that cause the engine to not start?

[Rbrucek]

Cleaned out heat exchanger and replaced impeller.