Truck Repair: n14 cummins, n14 cummins, paper element

Question
QUESTION: My n 14 cummins is losing prime most of the time over night or just in a few hours i had to change an injector that was bad and thats when the problem with losing prime started it does not do it all of the time but most of the time i have checked all lines are tight can the injector have something to do with it even though it runs great no miss or performance problems there

ANSWER: When you changed the injector did you lubricate the O-rings with engine oil before stuffing it? and did you take and make sure it was fully seated before putting on your holddown bolt. I doubt it's bad if its a new injector.

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QUESTION: I did put a light coat of grease on the o rings and i think it is seated right but there maybe something wrong there does it need to come out or look somewhere else does it have a check valve that could be bad anywhere it maybe sucking air somewhere to but where else to look the truck runs good after it starts

Answer
I think the place I would start is pulling that injector back out and check the orings and see if there was a snag and put on a new set of orings and put it back in. To make sure its seated I take a punch and hammer and the flange down at the base on each side I lightly tap there until I hear it make solid contact to the head. Just sounds weird to me that you haven't had a problem til the injector was replaced. If you have a davco filter that's the type has a paper element and a clear globe on top if your getting air in the system you'll be able to see bubbles through that globe. Only check valve I can think of is in the fuel pump but I wouldn't think it would act up all of a sudden after a repair.