Fuel Pressure: Testing and Inspection

Fuel Pressure Test

Special Tools Required
- Fuel pressure gauge 07406-004000B
- Fuel pressure gauge adapter 07VAJ-0040100

1. Make sure you have the anti-theft code for the radio, then write down the frequencies for the radio's preset buttons.
2. Disconnect the negative cable from the battery.
3. Remove the fuel fill cap.




4. Remove the intake manifold cover (A).




5. Use a wrench on the fuel pulsation damper (A) at the fuel rail.
6. Place a rag or shop towel (B) over the fuel pulsation damper.
7. Slowly loosen the fuel pulsation damper one complete turn.
8. Remove the fuel pulsation damper from the fuel rail.




9. Attach the fuel pressure gauge attachment and fuel pressure gauge.
10. Disconnect the vacuum hose (A) from the fuel pressure regulator (B) and pinch it closed with a clamp (C).
11. Reconnect the negative battery cable, then start the engine, and let it idle.
- If the engine starts, go to step 13.
- If the engine does not start, go to step 12.

12. Check to see if the fuel pump is running: remove the fuel fill cap and listen to the fuel fill port while an assistant turns the ignition switch ON (II), you should hear the pump run for about 2 seconds when the ignition switch is turned ON (II).
- If the fuel pump runs, go to step 13.
- If the fuel pump does not run, test it.

13. Read the pressure gauge (with the fuel pressure regulator vacuum hose disconnected and clamped). The pressure should be 320 - 370 kPa (3.3 - 3.8 kgf/sq.cm, 47 - 54 psi).
- If the pressure is OK and the engine is running, go to step 14. If the engine is not running, repair the cause, then continue this test.
- If the pressure is out of spec, go to step 14.

14. With the engine running, unpinch and reconnect the vacuum hose and read the gauge again. The pressure should be 260 - 310 kPa (2.7 - 3.2 kgf/sq.cm, 38 - 46 psi).
- If the fuel pressure is OK, the test is complete.
- If the pressure is out of spec, go to step 15.

15. Disconnect the vacuum hose from the pressure regulator again while you watch the pressure gauge. The pressure should rise when you disconnect the hose.
- If the pressure did not rise, replace the fuel pressure regulator.
- If the pressure rises, but all your readings were lower than specified, check for a clogged fuel filter and for leaks in the fuel lines.
- If the pressure rises, but all your readings were higher than specified, check for a pinched or clogged fuel return hose or line.

16. Reconnect the vacuum hose, remove the pressure gauge, and reinstall the fuel pulsation damper with a new washer. Tighten the fuel pulsation damper to 22 N.m (2.2 kgf-m, 16 lbf-ft).

NOTE: Disassemble and clean the fuel pressure gauge attachment thoroughly after use