Fuel Pressure: Testing and Inspection

TOOLS REQUIRED:

^ J 34730-1 A Fuel Pressure Gauge
^ J 39802-A Fuel Pressure Gauge Adapter

A fuel system pressure test determines if the fuel delivery system is functioning correctly from a fluid (gasoline) perspective. To perform this test, follow the procedure below.

1. Relieve the fuel system pressure. Refer to Fuel System Pressure Release Procedure.
2. Remove one bolt.
3. Remove fuel feed hose bracket from bottom of intake manifold.
4. Remove one bolt.
5. Remove the fuel feed hose from the fuel rail.
6. Install the J 39802-A with the gaskets and the fuel feed hose to the fuel rail.
TIGHTEN
^ J 39802 bolt to 29 Nm (22 lb. ft.).
7. Connect the J 34730-1A to the J 39802-A.
8. Connect the negative battery cable.
TIGHTEN
^ Negative battery cable-to-negative (-) battery cable terminal retainer to 15 Nm (11 lb. ft.).
9. Using a fused jumper, jumper terminals Fp to +B on the under hood DLC.
10. Turn the ignition switch to the ON position and allow fuel pressure to build.

MEASURE
^ The fuel pressure should be 265-304 kPa (38-44 psi). If pressure is higher than the specifications, check for a plugged fuel return pipe/hose. If pipe/hose are OK, replace the fuel pressure regulator. If pressure is lower than the specifications, check for leaks at hose-to-pipe connections, a leaking fuel pump or fuel pressure regulator. Repair/replace as necessary.

11. Start the engine.
12. Remove the fuel pressure regulator vacuum hose.
13. Plug the fuel pressure regulator vacuum hose.

MEASURE
^ Fuel pressure should be 265-304 kPa (38-44 psi) at idle.

14. Reconnect the vacuum hose to the pressure regulator.
15. Monitor the fuel pressure at idle.
16. The fuel pressure should drop to 206-255 kPa (31-37 psi).

NOTE: If pressure is not within specifications for the above mentioned tests, repair/replace the vacuum hose or fuel pressure regulator as necessary.

17. Turn the ignition switch to the off position.

MEASURE
^ Fuel pressure. Should remain above 147 kPa (21 psi) for at least five minutes after the engine was stopped. If pressure is below the specification, check for a leaking fuel pump, pressure regulator and/or fuel injectors.

18. Relieve the fuel system pressure. Refer to Fuel System Pressure Release Procedure.
19. Remove one bolt and the J 39802-A and the J 34730-1A from the fuel rail.
20. Using two new gaskets, reconnect fuel feed hose to fuel rail.
21. Secure fuel feed hose with one bolt.
TIGHTEN
^ Fuel feed hose bolt to 29 Nm (22 lb. ft.).
22. Reconnect the fuel feed hose bracket to intake manifold.
23. Secure fuel feed bracket with one bolt.
TIGHTEN
^ Fuel feed hose bracket bolt to 9.3 Nm (82 lb. in.).
25. Connect the negative battery cable.
TIGHTEN
^ Negative (-) battery cable-to-negative (-) battery cable terminal retainer to 15 Nm (11 lb. ft.).
26. Turn the ignition switch to the ON position and momentarily connect a jumper between DLC terminals +B and Fp to pressurize the fuel system. Check for any fuel leaks.