Fuel Pressure: Testing and Inspection

WARNING:
- Do not smoke while working on the fuel system. Keep open flames or sparks away from the work area.
- Be sure to relieve fuel pressure while the engine is OFF.

1. Relieve fuel pressure.
a. Disconnect the battery negative cable from the battery.
b. Remove fuel filler cap.
c. Use a box end wrench on the 6mm service bolt at the fuel rail, while holding the special banjo bolt with another wrench.

Fuel System Service Bolt:

d. Place a rag or shop towel over the 6mm service bolt.
e. SLOWLY loosen the 6mm service bolt one complete turn.
2. Remove the service bolt on the fuel rail while holding the banjo bolt with another wrench and attach the fuel pressure gauge.
3. Start the engine. Measure the fuel pressure with the engine idling and the vacuum hose of the pressure regulator disconnected.

Fuel Pressure Gauge:

Unregulated pressure should be:
240 - 279 kPa (35 - 41 PSI)

4. Reconnect the vacuum hose to the pressure regulator.

Regulated pressure should be:
200 - 240 kPa (29 - 35 PSI)

5. If the fuel pressure is not as specified, first check the fuel pump. If the pump is okay, check the following:
a. If pressure is higher than specified:
- Pinched, collapsed, or clogged fuel return hose or piping
- Faulty pressure regulator
b. If pressure is lower than specified:
- Clogged fuel filter
- Pressure regulator failure
- Leakage in the fuel system