Fuel Pressure: Testing and Inspection

Fuel System Pressure Test - Gasoline Engines





WARNING: Do not smoke, carry lighted tobacco or have an open flame of any type when working on or near any fuel-related component. Highly flammable mixtures are always present and may be ignited. Failure to follow these instructions may result in serious personal injury.

WARNING: Before working on or disconnecting any of the fuel tubes or fuel system components, relieve the fuel system pressure to prevent accidental spraying of fuel. Fuel in the fuel system remains under high pressure, even when the engine is not running. Failure to follow this instruction may result in serious personal injury.

WARNING: Do not carry personal electronic devices such as cell phones, pagers or audio equipment of any type when working on or near any fuel-related component. Highly flammable mixtures are always present and may be ignited. Failure to follow these instructions may result in serious personal injury.

WARNING: Always disconnect the battery ground cable at the battery when working on an evaporative emission (EVAP) system or fuel-related component. Highly flammable mixtures are always present and may be ignited. Failure to follow these instructions may result in serious personal injury.

WARNING: When handling fuel, always observe fuel handling precautions and be prepared in the event of fuel spillage. Spilled fuel may be ignited by hot vehicle components or other ignition sources. Failure to follow these instructions may result in serious personal injury.

All Engines

1. Release the fuel system pressure. For additional information, refer to Fuel System Pressure Release- Gasoline Engines Service and Repair.

2. Disconnect the battery ground cable.

6.2L (2V) engine

3. Install the Fuel Pressure T-Adapter 3/8" and Fuel Pressure Test Kit in line between the fuel supply line and fuel rail.





6.8L (3V) engine

4. NOTE: Use a commercially available fuel test adapter (such as OTC(R) 518527).
Install the Fuel Pressure Test Connector and Fuel Pressure Test Kit in line between the fuel supply line and fuel rail.






All engines

5. NOTE: The Fuel Pump Control Module (FPCM) electrical connector was disconnected during the fuel system pressure release and must be reconnected to complete the Fuel System Pressure Test.
Connect the Fuel Pump Control Module (FPCM) electrical connector.

6. Connect the battery ground cable.

7. NOTE: It may take more than one key cycle to pressurize the fuel system.
Cycle the ignition key and wait 3 seconds to pressurize the fuel system. Check for leaks before starting the engine.

8. Test the fuel system pressure to make sure it is within the specified range. For additional information, refer to Specifications.

9. NOTE: Open the drain valve slowly to relieve the fuel system pressure. This may drain fuel from the system. Place the fuel in a suitable container.
Upon completion of the fuel system pressure test, open the drain valve on the Fuel Pressure Test Kit and relieve the fuel system pressure.