Fuel Pressure Regulator: Testing and Inspection

WARNING: Do not smoke during the test. Keep open flames away from your work area. Be sure to relieve fuel pressure while engine is off.

1. Attach a pressure gauge to the service port of the fuel rail.
a. Disconnect the negative battery cable.
b. Remove the fuel tank filler cap.
c. Use a box end wrench on the 6mm service bolt at the top of the fuel rail, while holding the special banjo bolt with another wrench.

Fuel System Service Bolt:

c. Place a rag or shop towel over the 6mm service bolt and SLOWLY loosen the 6mm service bolt one complete turn.

Fuel Pressure Gauge:

d. Remove the service bolt on the top of the fuel rail while holding the banjo bolt with another wrench and attach the fuel pressure gauge.
2. Start the engine and allow it to idle. Measure the fuel pressure with the engine idling and vacuum hose of the pressure regulator disconnected.


Pressure at idle should be:
280 - 330 kPa (40 - 47 psi)

Fuel Pressure Regulator Return Hose:

3. Reconnect the vacuum hose to the pressure regulator.
4. Check that the fuel pressure rises when the vacuum hose is disconnected from the pressure regulator again.
- If the fuel pressure rises then the pressure regulator is good.
- If the fuel pressure did not rise, check whether it rises when the return hose is lightly pinched.
- If the pressure does not rise, replace the pressure regulator and retest.