alright after letting the truck sit for X amount of time, the intial start up is pretty rough with lots of white or raw fuel smoke. it will run rough for a few seconds as if there is air in the fuel then stall. (or run out of fuel) to get it restarted i will have to self prime it and it will crank over a few times then turn over and run great the remainder of the time until it sits again. Now im almost positive this is air in the fuel so ive replaced the rubber lines from fire wall up, the metal lines are in perfect shape. also the overflow valve has been replaced. latlety it has been seemingly getting worse in the amount of time is shorting for it t do this. in a previous post on the same topic i have been informed that the priming bulb could be leaking or the o rings could be letting air in. would it be worth it to buy a new lift pump for 80 some bucks from cummins. IMO it seems like its the lift pump but im looking for any other possible area to look at before buying the another stock pump or deciding to bite the bullet and getting an airdog or something.

 

when can u smell raw fuel? before u crank it? or like from the exhaust. have u checked ur oil, to see if its making any fuel?

 

what about your fuel level in your tank could it be sucking air there maybe from your supply tube

 

smells like fuel from the exhaust its a real think white smoke, oil level is fine. and it could be from the tank. how would i be able to tell for sure? drop the tank and look at the draw straw?

 

sounds to me like u have an injectors leaking down bud if u can smell raw fuel out the exhaust

 

well i guess i would be hard to say for sure since am in the truck but the smoke is deff thick white smoke but it only does it briefly if i step on it to raise the RPMS to try to feather it out from stalling. if i dont attempt to give it fuel while it is running rough it wont smoke. the whole process only takes like thirty seconds once i re prime the truck fires immediatly and will run flawlessly until i go to start it again after siting for a day or more.

 

sounds like injectors to me. are you still running the stock injectors?

 

yep their still the stock injectors the truck has 175k on it. so it might me time for some sticks. so explain to me what is happening if it is the injectors so i better understand. is their a ball check type valve in them that is suppose to seal when pressure is not applied and if it is wore out they will leak fuel on the tops of the pistons. if this is so why would the truck run rough for a few then stall only to run fine again after re primeing and thanks guys for the input its a huge help ive been thinking it must be the lift pump or the draw straw dry rotted and is sucking air i never really thought about injector problems seeing as the truck runs great besides this problem

 

there is a needle valve, and after a long time, they will not seal properly, and leak a lil

 

alright i understand now, so is there a way to rule out one over the other, if it turns out to be injector related ill throw some small sdx in there as this is more or a street daily driver, but i guess i could take a look at the lift pump as well im sure its in needing of being replace if its still the factory one. how much hp can a stock lift pump fuel?