Test NF-3A - Checking Fuel Pressure
WARNING:
High fuel pressure may be present in fuel lines. Open fuel system with caution. See FUEL PRESSURE RELEASE procedure in this article.
- Relieve fuel pressure. Connect fuel pressure gauge to fuel rail. Turn ignition switch to ON position. Using DRB-II, actuate fuel system. If fuel pressure is 32-49 psi, fuel pressure is okay. If fuel pressure is not 32-39 psi, record fuel pressure reading. If fuel pressure is more than 49 psi, perform TEST NF-3B.
- If fuel pressure is less than 49 psi, stop fuel system actuation. Turn ignition switch to OFF position. Inspect fuel lines for kinks and restrictions. Repair as necessary. Perform VERIFICATION PROCEDURE VER-2.
- If lines are not kinked or restricted, remove fuel pressure gauge from fuel rail. Install fuel pressure gauge between fuel tank and fuel filter. Turn ignition switch to ON position. Using DRB-II, actuate fuel system. If fuel pressure is at least 5 psi more than previously recorded, replace fuel filter. Perform VERIFICATION PROCEDURE VER-2.
- If fuel pressure is not at least 5 psi more than previously recorded, gently squeeze fuel return hose while observing fuel pressure gauge, ensuring fuel pressure does not exceed 50 psi. SeeFigure . If fuel pressure increases, replace fuel pressure regulator. Perform VERIFICATION PROCEDURE VER-2. If fuel pressure does not increase, replace fuel pump and sock assembly. Perform VERIFICATION PROCEDURE VER-2.