To perform general checks on the fuel system, first ensure that there is enough fuel in the Fuel Tank. Then, verify that the fuel pump is running by having an assistant turn the ignition switch to ON and listening for a whirring noise indicating the pump is pressurizing the system. If there is no sound, check the EFI fuse and the circuit opening or EFI relay. If these are fine, check the wiring back to the fuel pump. If voltage is present at the fuel pump connector, the pump is defective, but if there is no voltage, the PCM may be faulty. For a fuel pump pressure check, relieve the fuel system pressure. For four-cylinder models, a fuel pressure gauge and T-fitting are needed to measure the pressure. Disconnect the fuel supply line from the fuel rail and connect the gauge between the line and the rail using the T-fitting. For V6 models, a fuel pressure gauge, hose, and adapter are required. Remove the engine cover and unscrew the banjo bolt securing the crossover line to the front fuel rail. Screw the adapter into the rail and connect the fuel pressure test hose. For 2GR-FKS engines, disconnect the low-pressure side fuel delivery line and connect a special service tool between the connections. With the engine off, turn the ignition switch to ON and note the reading on the gauge. Start the engine and check if the pressure remains the same. If the pressure is not within specifications, check the fuel pressure regulator, fuel line, and fuel filter. If necessary, replace the fuel pressure regulator and pump. Leaking fuel injectors could also cause low pressure. After testing, relieve the pressure, reconnect the fuel line or crossover line, and check for leaks when starting the engine.
