Fuel delivery?

[DKeen]

Strange problem. My truck is not getting good fuel pressure at the filter. If I take a air hose and blow back into the tank from the Fuel pump, I will get good pressure for a while. I have replaced the original tank with a plastic one. Could the sock in the sending unit collapse?

[Hubert]

Well, I have had one plug up with rust so they can restrict flow. Plastic tank not sure what would plug it a bacteria growth in tank maybe ??? big ? there. Have you checked that it is not creating a vaccum in tank? I don't think the LP with pull much of a vaccum and its a theory that restricted flow is partially to blame for some failures.

[twaddle]

Is the fuel tank cap venting ok?

Jim Twaddle
Biggar, Scotland

[DKeen]

The plastic tank in new and I have ran it with the cap loose. Some issue. Sounds like I might have to drop it and inspect it again!! Bought the plastic tank because of the rust in the metal one (GM's denial of warranty claim!!!)

[tom.mcinerney]

plastic should be OK. Is the sender unit new? Is it OEM?

The sendor's have an overide valve that allows fuel to bypass a clogged intake sock/screen, but if tank low can suck air if valve ajar, or pickup pipe rusted pinhole.

The filter assemblies can leak . Did you bleed air from yours?