Fuel Pressure: Testing and Inspection

SST Fuel Gauge With Pressure Release Hose:

Fuel Pressure Hold Inspection

Warning: Before performing the following operation, release the fuel pressure from the fuel system to reduce the possibility of injury or fire.

1. Install the SST.
2. Connect SST (NGS) to the data link connector and select active command mode.
3. Select Fuel Pump Relay control. Turn relay on for 30 seconds.
4. Turn relay off.
5. Observe the fuel pressure.

Fuel pressure: 240-280 kPa (35-40 psi)

6. Observe the fuel pressure after 1 minute.

Fuel pressure: Within 34 kPa (5 psi) of reading in test step 5.

7. If not as specified, perform the following inspections:
^ Fuel pump
^ Pressure regulator
^ Injector fuel leakage

SST Fuel Gauge With Pressure Release Hose:

Fuel Line Pressure Inspection

Warning: Before performing the following operation, release the fuel pressure from the fuel system to reduce the possibility of injury or fire.

1. Install the SST.
2. Connect SST NGS to the data link connector and select active command mode.
3. Select fuel pump relay control. Turn relay on.
4. Measure the fuel line pressure.

Fuel line pressure: 240-280 kPa (35-40 psi)

Zero or
pressure low - Check the fuel pump. If as specified, the fuel line or fuel filter might be clogged or restricted.
Pressure high - If the fuel return line is not restricted, then replace the pressure regulator.

SST Fuel Gauge With Pressure Release Hose:

Fuel Line Pressure Under Load Inspection

Warning: Before performing the following operation release the fuel pressure from the fuel system to reduce the possibility of injury or fire.

1. Install the SST.
2. Disconnect the vacuum hose from the pressure regulator and plug it.
3. Start the engine and drive the vehicle under heavy acceleration.
4. Verify the fuel line pressure does not increase or decrease more then 2O kPa (3 psi) during heavy acceleration.
5. If not as specified, inspect the fuel filter and the fuel vapor valve.