Originally Posted by PaulDaisy

+1 for air leak on the suction side.
There is a simple test: install a piece of clear line (teflon or nylon) before the IP or fuel filter and watch for air.
-P

Originally Posted by SBishop

What was the fuel level when you have the problems?
Somewhere in the far recesses of my dim memory I remember reading about the fuel line in the tank rubbing against a screw and getting a hole in it and at lower fuel levels sucking air into the system.