LB7: lb7 wont run

[garychev]

I have a 2001 silverado Lb7 motor, It was getting hard t start now it doesnt stay running, I prime the air out of the filter and it vranks 10 times and fires up runs about a minute and dies, then when I bleed it again the fuel in the filter comes out like foam or suds, any ideas injector pump, injectors or maybe just lines?

 

[Hole Shot]

Try pumping the primer with the bleader screw tight and see if there is a leak at the water sensor, or in any of the lines at the fuel filter block.

 

[garychev]

I tried that and i put a gauge on it and it held 15 psi in the fiter and even took the one off my lbz and tried it and did the same thing

 

[sparepartsracing]

sounds like a cracked fuel filter housing i had this problem...either replace it or get a lift pump

 

[garychev]

I thought so until i swapped the housing and it still did it

 

[sparepartsracing]

yup your having the same problem i did...sorry i worded my problem wrong i bypassed my factory fuel filter housing....added a lift pump and aftermarket fuel filter on the frame and my problem was fixed

 

[garychev]

i might give it a shot ,PPE any good? ya know what causes this problem?

 

[sparepartsracing]

i have an airdog 150 and no complaints....no i never figured it out...noone seemed to know either i tried alot of things...theres no leaks...only thing i could think of was maybe a weak cp3

 

[garychev]

thats what i was thinking because i primed the system with the primer and had the outlet plugged to see if it lost pressure and it didnt It only lost it with the outlet to the engine, other than that it runs fine except when its dying theres a little puff of white smoke once in a whle i actually get it running long enough to drive it around then I turn it off and thats it, I think ill try the pump is there alot involved in the install?

 

[sparepartsracing]

yeah i have to used to prime mine evertime i started it...and when it would run it would only do 1/2 throttle otherwise it would blow gray smoke and go nowhere ha ha

 

[garychev]

Im still alittle worried about injectors dealer did the four on one side while under warranty not the other side I have 93000 on it now but over the 7 years no fuel in oil though, think ill try the injectors haha

 

[sparepartsracing]

well if you pickup a handheld tuner...you can get one for under 300...you can check your flow rates....+/-4 park +/-6 in drive..

 

[garychev]

yea trying to get my friend over with his snap on to check it, I wrote wrong on the last one meant to say think ill try the lift pump before the injectors, a whole lot cheaper and easier think ill def. check those flow rates before anything though if I can keep it running long enough ,Thanks for the info

 

[sparepartsracing]

no prob but im 90% sure the lift pump will fix your problem:thumb:

 

[garychev]

hope so! cheapest way out, il get back on when I know something

 

[sparepartsracing]

ok keep up posted....i bought mine off of xtreme diesel performance or xdp and used some coupon codes they were the cheapest

 

[JMK777]

check your fuel line from the tank all the way to the filter for leaks/cracks/collapsing.Or try disconnecting the fuel supply line to the filter housing and supplying fuel with a small tank to see if the lines pre filter lines are bad.

 

[garychev]

Ill try that too, thanks

 

[garychev]

Ok, today I disconnected the filter inlet and put a clear hose down to a 5 gallon can of diesel she runs perfect! so next i guess to find the bad line

 

[garychev]

Well, My fuel lines just came in from Gm mine were rotted, I bought the whole thing tank to motor with the cooler, dealer wanted 1000.00 got them on gmpartscenter.net for 600.00, put them in and the truck fires right up and runs great , thanks everyone for your help