Always wear safety glasses when working on your vehicle. Wear other personal protective equipment (PPE) when necessary, for example latex gloves or closed toe shoes.
Disable the fuel pump and relieve the fuel system pressure.
Disconnect the fuel line and install a fuel pressure gauge. Reconnect the fuse to the fuel pump.
Start the engine and check for leakage around the gauge connections.
Disconnect the vacuum hose from the fuel pressure regulator and attach a hand held vacuum pump to the port on the fuel pressure regulator.
Read the fuel pressure gauge when a vacuum is applied to the fuel pressure regulator and also when no vacuum is applied. The fuel pressure should decrease as vacuum increases, and increase as vacuum decreases. Compare your readings with the value in your vehicle's specifications.
Reconnect the vacuum hose to the regulator and check the fuel pressure at idle, comparing your reading with the value in your vehicle's specifications. Disconnect the vacuum hose and watch the gauge â the pressure should jump up as soon as the hose is disconnected. If it doesn't, proceed to step 8.
If the fuel pressure is low, pinch the fuel return line shut and watch the gauge. If the pressure doesn't rise, the fuel pump is defective or there is a restriction in the fuel feed line. If the pressure rises sharply, replace the fuel pressure regulator.
If the fuel pressure is too high, turn the engine off. Disconnect the fuel return line and blow through it to check for a blockage. If there is no blockage, replace the fuel pressure regulator.
Connect a vacuum gauge to the fuel pressure regulator vacuum hose. Start the engine and check for a vacuum. If there isn't a vacuum present, check for a clogged hose or vacuum port. If the amount of vacuum is adequate, replace the fuel pressure regulator.
Before replacing the fuel pressure regulator, relieve the fuel system pressure again. Disconnect the cable form the negative battery terminal.
Clean any dirt from the around the fuel pressure regulator.
Detach the vacuum hose from the fuel pressure regulator.
Remove any bolts that attach the fuel pressure regulator to the fuel rail and remove the fuel pressure regulator.
Install new O - rings on the fuel pressure regulator and lubricate them with a light coat of oil.
Tighten the fuel pressure regulator mounting bolts securely.
Verify this repair has been properly completed by using a vacuum gage. If the readings on the gage match manufacturer's specifications the repair has been successfully completed.
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