wont start

[kenmartin]

well guys the truck was running fine when i was using a 5 gallon fuel tank, after i hooked it up to the fuel tank of the truck it would run for about 5 seconds then die, and now it is not starting at all, i have bleed the fuel injector lines and still get a little bit of bubbles, should it start still? i am just running the stock lift pump and have went back to using the 5 gallon tank again, the hand primer doesnt seem to be working all the time! what should i look for now? thanks for your time

[jogl]

If there are bubbles coming out of the injector lines it is unlikely to start.

When you used the 5 gallon pail was the pail sitting higher in elevation than the lift pump, filter and IP?

You obviously have a leak. If you had the pail sitting on the roof of the cab (like I do when trouble shooting) the leak could still be in the LP, filter or IP or the lines in between. (Assuming that you had the pail plumbed into the LP) The two feet of head may have kept air from getting in. If the pail was sitting on the floor then the leak is probably in the lines coming from the fuel tank or in the fuel sending unit itself.

If the lobe on the cam shaft that drives the LP is in the wrong place then you won't be able to use the hand primer. Just turn the motor over a half revolution with the starter.

You need to find and repair the leak and then you will only have to bleed it out one last time.

Good Day,
JP.

[Tacoclaw]

Are you still using the Hummer LP? Did you check this out? On my truck, the factory sender doesn't show pressure for a good 15 seconds. That may be enough time for the vane pump to pull a vacuum behind the lift pump and suck air somewhere between them.

What pressure does the electric pump on that Hummer put out? Is there a chance that it's sucking the filter dry before oil pressure comes up and kicks the pump on? Even a little air is bad, so the vane pump on the VE may be pulling a vacuum in the lines after the LP. A tiny air leak there would probably not show itself once the LP gets power and kicks on, filling them with fuel again.

[kenmartin]

thanks guys for the info i will try tommorrow, as for the lift pump i was using it and you are right it doesnt provide a constant supply of fuel, do you think i can wire to run when the key is on? its a very dependable lp!