Fuel Pressure Regulator Inspection
- Release fuel pressure. See FUEL PRESSURE RELEASE . Connect fuel pressure gauge to fuel inlet line at fuel rail. Start engine and run at idle. Record fuel pressure. Disconnect and plug vacuum line at fuel pressure regulator. Drive vehicle under heavy acceleration while monitoring fuel pressure. If fuel pressure holds steady within 3 psi of recorded fuel pressure, go to next step. If fuel pressure did not hold steady, check Fuel Vapor Vent (FVV) valve. See SYSTEM TESTS (EVAPORATIVE EMISSION) in SYSTEM AND COMPONENT TESTING article. If valve is okay, check for clogged fuel filter. Repair as necessary.
- Connect vacuum pump to fuel pressure regulator and apply vacuum. If fuel pressure decreases, check for leaking vacuum hose. If fuel pressure does not decrease, replace fuel pressure regulator. Go to next step.
- Disconnect fuel return line from fuel rail. Connect a short hose from fuel rail to a one liter measuring container. Turn ignition switch on. Engine off. Connect scan tool to DLC. Select PCM, Active Command Modes and OUTPUT TEST MODE. Press MODE to change to ALL ON mode. Press START, to run fuel pump. Measure fuel line pressure and ensure fuel is flowing into container. If fuel pressure or volume is high, replace fuel pressure regulator. If fuel pressure or volume is not high, check return line for blockage or clog. Repair as necessary. Go to next step.
- Start engine and let run for 10 seconds. Turn ignition switch off. Restart engine and let run for 10 seconds. Turn ignition switch off. Remove vacuum hose from pressure regulator and check for fuel in hose or pressure regulator. If fuel is present, replace fuel pressure regulator.