Failed fuel delivery?

Tire repair service truck came in on a hook customer stated they had fixed it but not good enough to run more than 40 MPH and then it shut off on them while going to a service call. Fuel rail pressure wouldn't go above 9.7 lbs disconnected fuel line from fuel filter on tank side, no fuel would come out. Blew air into line acts as if its dead headed. Removed tank end of line not blocked it appears someone has replaced the fuel line connectors on tank with some from another vehicle. I would like to start with a diagram of lines and wiring. Oh, yeah, I almost forgot with fuel filter line unhooked it runs but with only 9lbs of fuel PSI on rail.