losing prime somehow
 

ok so my truck is doin somethin stupid. here recently it has been losing prime or sucking air from somewhere and idk where. it will just die without a moments notice and i can bleed the lines and it will start back up and run just fine. got no clue whats goin on here.
thanks for any replies.

Lift pump is not running when the engine is would be my guess.

it runs i an feel it when the truck is runnin but whether its actually pumping is a good question

do the LP test when running open the T-Valve and get jar or something and it should pump about 3qts in a min

twist the fuel filter cap open
take the relay cap off the fuel pump relay and jump it. (with the truck on, not started).
if it barely comes out, its be the lift pump.
HOWEVER, i did my lift pump and after running at a higher psi, i found that my fuel lines were junk.

hope this helps!

Yep, do a pressure test, check for loose wires, or fuel line clamps. Or i have seen rusty lines on the older diesels cause that.... Hope you find the trouble:tu:

well i had some problems with fuel lines breaking when i replaced a head gasket so i dont have a t valve anymore but it just dies when i try to purge it so im guessing the Lp is bad. the wierd thing is its only just over a year old:argh:

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thanks everybody for the replies

I had this exact problem. Its the diaphragm in your LP. They're only 20 bucks. Just replace it. I just did mine yesterday, and it runs great now. Make sure you grease up the push rod when you're installing the new LP, or else it will be a nightmare... Trust me.