when does fuel pump operate?
No pressure when i turn on the key but 10 psi when it is running. Is the pump
supposed to run with the key on not just when cranking? 1989 D150 5.2L
That is low pressure for running,and no the pump want run but a few seconds when you just cut key on,sounds like the pump might be getting weak.
Ans if you havent change the fuel filter may try it first before replacing pump.