Fuel Pressure: Testing and Inspection

WARNING: Do not smoke while working on the fuel system. Keep open flames or sparks away from your work area. Be sure to relieve fuel pressure with the ignition switch OFF. It is recommended that the battery be disconnected before any fuel system work is to be done.


NOTE: The radio may have a coded theft protection circuit. Be sure to get the customer's code number before disconnecting the battery. After service, reconnect power to the radio and turn it on. When the word "CODE" is displayed, enter the customer's 5-digit code to restore radio operation.

Fuel Pressure Release and Test Port:

1. Disconnect the battery negative cable from the battery negative terminal.
2. Remove the fuel fill cap.
3. Use a box end wrench on the 6 mm Fuel Pressure Test Port at the fuel rail, while holding the special banjo bolt with another wrench.
4. Place a rag or shop towel over the 6 mm Fuel Pressure Test Port.
5. Slowly loosen the 6 mm Fuel Pressure Test Port bolt one complete turn.

NOTE:
^ Always replace the washer between the Fuel Pressure Test Port and the special banjo bolt whenever the service bolt is loosened.
^ Replace all washers whenever any other fuel fitting bolts are removed.

Checking Fuel Pressure:

6. Remove the port bolt on the fuel rail while holding the banjo bolt with another wrench and attach the fuel pressure gauge.
7. Start the engine. Measure the fuel pressure with the engine idling and the vacuum hose of the pressure regulator disconnected and plugged.

Pressure At Idle Should Be:
2.7-3.2 kg/cm2 (38-46 psi)

8. Reconnect the vacuum hose to the pressure regulator.

Pressure At Idle Should Be:
2.1-2.6 kg/cm2 (30-37 psi)

9. 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
^ Defective Fuel Pump