1998.5 24 valve cummins need help(losing prime)

[huffjdeere]

If I let my truck set for more that about 8 hours it seems to lose prime. It will start up and run for about 5 secs and then die. Then I will have to bleed the fuel filter and bump the starter to allow the lift fuel pump to reprime. This usually takes 5 mins or so of bleeding and turning the key on and off and letting the lift pump run. Originally I thought the lift pump was not holding its prime once it set too long, so I went ahead and replaced that cause I hadnt replaced it in about 3 years and am always afraid of ruining my injection pump if the lift pump goes out. Anyways I still cant seem to find the reason that my cummins is losing prime???? Any direction and advice as to where to look next is greatly appreciated. Also, once I get it going after repriming it runs just fine and seems to be getting plenty of fuel so I am hoping I dont have a problem with my injection pump.

Thanks in advance for any help
huffjdeere

[upinsmoke53020]

Had similar problem on mine. Had to replace sending unit because it had a leak and was sucking air.

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99 Dodge Ram 2500, 5-speed, Edge Juice w/attitude and HOT unlock! Banks monster exhaust, BHAF, Pro Comp 33X12.50R17, Boost, Pyro pillar guages. Silencer ring, muffler, rear tire tread MIA

[still strokin]

had similar problem with mine had hole in fuel line. Had to replace line from tank

[huffjdeere]

If this was the case(that I had a whole in the line somewhere so it was sucking air) would it still run just find after getting it to start up?? The idea of a hole in a line somewhere makes sense but I am just curious as to why it will run fine with plenty of fuel once I get it going? Im sure it would take just a very small pin hole to cause this problem and maybe thats why I havent noticed any fuel on the ground once it sets over nite.
thanks for the replies

[farmboysdiesel]

Sounds like a good time to put a fuel system on and bypass the stock stuff.

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[dieseldude5.9]

ya I would think if it had a leak in the suction part of the line from the tank to the lift pump it would be sucking air into the system and causing it to run rough and low power, but if it was on the pressure side of the lift pump it would leak fuel out while it running.

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05' QC, AFE Stg 2, 4" MBRP turbo back

[upinsmoke53020]

What happens when you have a leaking fuel line is that the VP44 actually turns itself into a vaccuum. BAD!! Once the
VP44 has primed itself, it will run just fine. But, your VP will not survive very long if you keep running it like that!!

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99 Dodge Ram 2500, 5-speed, Edge Juice w/attitude and HOT unlock! Banks monster exhaust, BHAF, Pro Comp 33X12.50R17, Boost, Pyro pillar guages. Silencer ring, muffler, rear tire tread MIA

[upinsmoke53020]

Do you have a fuel pressure guage??

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99 Dodge Ram 2500, 5-speed, Edge Juice w/attitude and HOT unlock! Banks monster exhaust, BHAF, Pro Comp 33X12.50R17, Boost, Pyro pillar guages. Silencer ring, muffler, rear tire tread MIA

[bbraden]

Originally Posted by farmboysdiesel

Sounds like a good time to put a fuel system on and bypass the stock stuff.

second the part about replacing all that mess... it's a pretty good idea at this point... it'll make sure you DON'T smoke your VP

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99 dodge 4x4 13" Proluk Gold clutch, BHAF-K&N combo, Super X VP44, FASS, Edge comp, MODIFIED Super B Turbo, RV 275's, Quick spool manifold, 4" MBRP straight back, 3.55's, BFG A/T 285's!, somewhere north of 400 hp