Fuel Pressure: Testing and Inspection

Fig 6 Fuel Pressure Test Port:

WARNING: Fuel system pressure must be released before a fuel system hose or component is disconnected.

The fuel system operates at approximately 338 kPa (49 psi). Check fuel system pressure at the test port on the fuel rail (Fig. 6).

1. Remove cap from fuel pressure test port on fuel rail.

Fig 7 Checking Fuel Pressure At Fuel Rail:

2. Connect Fuel Pressure Gauge C-4799B to test port (Fig. 7).

CAUTION: When using the ASD Fuel System Test, the ASD relay and fuel pump relay remain energized for 7 minutes or until the test is stopped, or until the ignition switch is turned to the Off position.

3. Place the ignition key in the ON position. Using the DRB scan tool, access ASD Fuel System Test. The ASD Fuel System Test will activate the fuel pump and pressurize the system.
- If the gauge reading equals 338 kPa (49 psi) further testing is not required. If pressure is not correct, record the pressure.
- If pressure is above specifications, check for a kinked or restricted fuel return tube (from filter to pump module). If the fuel return tube is not pinched or restricted, replace the fuel pressure regulator.
- If fuel pressure is below specifications, refer to the diagnosis chart for Fuel Pressure Below Specifications.
4. Replace pressure test port cap when finished performing pressure test.

Fuel Pressure Below Specifications: