Test NS-4D - Repairing Low Fuel Pressure
WARNING:
High fuel pressure may be present in fuel lines. Open fuel system with caution. See FUEL PRESSURE RELEASE .
- Record fuel pressure reading. Turn ignition off. Release fuel pressure. Remove fuel pressure gauge. Install fuel pressure gauge between fuel tank and fuel filter. Turn ignition on. Go to next step.
- Using scan tool, actuate ASD fuel system. Record fuel pressure gauge reading. Compare 2 fuel pressure gauge readings. If fuel pressure is at least 10 psi (0.7 kg/cm2 ) more, go to next step. If fuel pressure is not at least 10 psi (0.7 kg/cm2 ) more, go to step 4).
- Turn ignition off. Inspect fuel lines between fuel filter and fuel rail for a restriction. If a restriction is present, repair as necessary. Perform TEST VER-1A. If a restriction is not present, replace fuel filter. Perform TEST VER-1A.WARNING: DO NOT allow fuel pressure to exceed 70 psi (4.9 kg/cm2 ) during next step.
- Turn ignition off. Release fuel pressure. Disconnect fuel return hose at fuel rail. Connect a 6 foot fuel hose to fuel rail. Place other end of 6 foot fuel hose into an approved 2 gallon or more capacity fuel container. Go to next step.
- Turn ignition on. Using scan tool, actuate ASD fuel system. Observe fuel pressure gauge while gently squeezing 6 foot fuel hose. Using scan tool, stop ASD fuel system actuation. If fuel pressure was more than 43 psi (3.0 kg/cm2 ), replace fuel pressure regulator. Perform TEST VER-1A. If fuel pressure was not more than 43 psi (3.0 kg/cm2 ), replace fuel pump and sock filter. Perform TEST VER-2A.