Fuel Pump Testing

The fuel pump ciruit has several components that can fail. Be sure to test the system before pulling the tank and replacing the pump.

Circuit DescriptionThe ECM (computer) will turn the pump ON whenever the ignition switch is in the RUN position. The pump will remain ON for approximately 3 seconds or until you begin cranking. It will also remain ON as long as the engine is cranking, running and the ECM is getting ignition reference pulses.
The pump will deliver fuel to the pressure regulator which will limit the fuel pressure to 34-46psi(V6) and 9-13psi(4cyl). Any excess pressure is sent back down to the fuel tank via the fuel return line.
Start with the Simple ThingsAlways start by checking the most simple and commonly overlooked items such as the fuses and ground.
The fuel pump runs on a 10 amp fuse and should be checked before going any further. Also check the 5 amp injector fuses. If the fuses are good, then check the gound. The fuel pump ground are located in the center console, just forward of the computer.