Hello,

I am still fighting the air in the filter housing problem. You bleed all of the air out and drive the truck. A few minutes later when you get back in ...the truck won't start...you have to crank and crank...or get out and bleed the air again. I have checked out the housing and the line to the injector pump.

Lift pump is new and operates when you jump the oil pressure switch...that's how I bleed the filter. You don't even have to have the ignition on..you can jump it and it runs?

My question is...when does this pump run? I know it runs when cranking the motor...but does it stay running after the truck starts or is it controlled by filter bowl level?

I would really like to know where it is getting the air back into the housing after being bleed and run. The next item I am going to check on is the past owner had a inbed fuel tank...removed it when he sold the truck and he just cut the fuel line that went the the extra lift pump he added. I plugged it but it didn't help.

I am sorry this is so long but would appreciate anybodys insight into the air mystery.

Bill- Cpcycles

OPS is the weak link, wire LP power off an ignition wire or relay off a new OPS, but it will fail again on you.

As you suggested, check out the additional plumbing from the removed auxiliary lift pump.

Then check out the oem fuel lines for wet spots, which would indicate leakage..

Then check that the lift pump is vibrating when the engine is running, and that fuel shoots out the air bleed, and does not shut the engine off.

KISS, you know, look for the obvious first. I’ll bet your problem lies here: "the past owner had a inbed fuel tank...removed it when he sold the truck and he just cut the fuel line that went the the extra lift pump he added". Look for air being drawn into the system before the lift pump. Everything beyond the lift pump should have positive pressure meaning that a fuel leak would show, not air being sucked into the system. The lift pump should work off the relay at startup and then the oil pressure switch takes over as a safety. Oil pressure > 4lbs. /sq. in. I think. The theory is that the fuel would be cut in an accident by the engine stopping causing the oil pressure to zero hence stopping the supply of fuel being pumped to the engine. Your truck can run without the lift pump working but will have fuel supply problem symptoms. Lacks of power feeling or missing on hard excel, high speed travel.

Thanks for all the replies. It is great to have a place where people have the same interest and sincere about helping others. Thanks everybody!

Bill- Cpcycles