Fuel Pressure: Testing and Inspection

NOTE: Obtain code number and deactivate audio anti-theft system before disconnecting battery. Refer to ADJUSTMENT PROCEDURES.

WARNING: Before disconnecting any fuel line, release fuel pressure with the following procedure. When replacing fuel system components, keep sparks, cigarettes and open flames away from fuel. Use a rag as protection from spray when disconnecting hoses. Plug hoses while they are disconnected.

RELIEVING FUEL SYSTEM PRESSURE

Relieving Fuel System Pressure:

1. Start engine.
2. Disconnect fuel pump relay (circuit opening relay) connector.
3. After engine stalls, turn ignition "OFF."
4. Reconnect fuel pump relay connector.

FUEL LINE PRESSURE CHECK

Pressure Regulator Testing:

1. Disconnect negative battery terminal.
2. Connect fuel pressure gauge between fuel rail and main fuel hose. Install clamps at all connections.

NOTE: The main fuel hose is attached to the front of the fuel rail. The return hose is attached to the pressure regulator.

3. Reconnect negative battery terminal.
4. Start engine and run at idle. Check fuel line pressure.

LINE PRESSURE: 31 - 38 psi (216 - 265 kPa)

5. If line pressure is not as specified, check hold pressure.

HOLD PRESSURE CHECK

Fuel System Priming:

WARNING: Before performing this test, relieve fuel pressure as previously described.

1. Disconnect battery negative terminal.
2. Install fuel pressure gauge as described above.
3. Reconnect battery negative terminal.
4. Connect a jumper wire across diagnosis connector terminals "F/P" and "GND."
5. Turn ignition switch "ON" for ten seconds to operate fuel pump.
6. Turn ignition switch "OFF" and remove jumper wire.
7. With an appropriate clamping tool, block fuel return hose (outlet hose from pressure regulator).
8. Observe pressure gauge for five minutes to ensure that fuel maintains specified pressure.

HOLD PRESSURE: Greater than 21 psi (147 kPa)

9. If not as specified, check for possible problems such as leaking injectors, leaking hoses or connections or defective fuel pump.
10. Repair any problems detected and recheck. If pressure is still not as specified, replace pressure regulator.