Toyota 23221-21030 Fuel Pump Assembly

To check the fuel pump, switch on the ignition and listen for the sound of the electric motor running beneath the rear seats. If the pump doesn't run, check the fuse, relay, and wiring. Connect a fuel pressure gauge in the fuel line at the rear of the engine compartment and start the engine. Note the gauge reading once the pressure stabilizes. High pressure indicates a faulty fuel pressure regulator, while low pressure could be due to a faulty regulator, low voltage, a blocked Fuel Filter, or a faulty pump. After turning off the engine, verify pressure remains for five minutes. Disconnect the gauge, depressurize the system, clean up any spills, and check for fuel leaks while running the engine.