So this occurred after disconnecting the fuel lines. My thoughts are to check the connections to eliminate air possibilities, also I owned a Thunderbird that had a fuel shut off switch that killed the power to
the fuel pump if the vehicle experienced an impact. A small rear end collision and the fuel pump shut off. There is a reset button somewhere. That was a 1985. The possibilities that the fuel pump died at this
time seem odd. Time to get a wiring diagram of the chassis and look for that shut off switch IF there is one. A clogged fuel filter, one that is hidden inside of the frame rails is also possible. Striking the coach
with a hammer to install parts may set off a switch if it is weak. IMHO.