Can a mechanical fuel pump lose its prime?
Sometimes mechanical pumps start leaking through the diaphragm into the crankcase. Or the fuel line might have a small crack that lets the gas drain back down the line. Mine had cracked and leaking fuel lines. Once replaced it never loses prime.
What is priming the fuel pump?
In a priming application, where the fuel pump is only used during start up or when the fuel system has been drained completely of fuel, a priming pump is installed to prime the fuel system instantly and push fuel into the injection system. This allows the engine to start quickly and avoids unnecessary engine cranking.
Why does my fuel pump not prime when I turn it on?
Pulled fuel pump relay and put in a jumper wire to run the fuel pump and it started. Put the fuel pump relay back in and it starts and drives, but the fuel pump still doesn’t prime when turning the key on. I’m afraid that after sitting overnight, it will once again refuse to start.
Why is the fuel pump relay not closing?
If jumping the fuel pump relay makes the pump run, and if the relay tests good. Then you need to determine why the ECM is not telling the relay to close. Start by testing continuity back to the ECM. Here is the electrical diagram for the 01 Tib Fuel Pump Relay
What should fuel pressure be when no Buzz?
Fuel pressure is typically in the 35 to 45 psi range. If your Anti-Theft light is flashing; the anti-theft system is disabling the fuel pump to prevent the engine from starting. Bad fuel pump (Pump should run for a few seconds when ignition key is turned to start, no buzz means no fuel delivery to the engine).
Where to check for no start fuel pump?
The first thing you want to do is check the fuse panel to see if the fuse is blown. If your car has two fuse panels than the one in the engine compartment; should be the correct one to check. The fuse panel or circuit box is usually located near the battery; and is a small black box with a removable lid.