Grand Marquis V8-4.6L Flex Fuel (2010)
Fuel Pressure: Testing and Inspection
Fuel System Pressure Test
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: 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: 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: 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.
1. Release the fuel system pressure. For additional information, refer to Fuel System Pressure Release See: Fuel Filter/Fuel Pressure Release/Service
and Repair.
2. Disconnect the battery ground cable. For additional information, refer to Battery.
3. Disconnect the fuel tube-to-fuel rail spring lock coupling. For additional information, refer to Spring Lock Couplings See: Powertrain
Management/Fuel Delivery and Air Induction/Fuel Line Coupler/Service and Repair/Spring Lock Couplings.
4. Install the Fuel Pressure Test Kit inline between the fuel tube and the fuel rail.
5. NOTE: The Fuel Pump (FP) module fuse was removed previously in the Fuel System Pressure Release.
Install the FP module fuse.
6. Connect the battery ground cable. For additional information, refer to Battery.
7. NOTE: Carry out a Key ON Engine OFF (KOEO) visual inspection for fuel leaks prior to the Fuel System Pressure Test.
NOTE: After completion of the Fuel System Pressure Test, open the drain valve on the Fuel Pressure Test Kit and release any residual fuel into a
suitable container prior to removing.
Test the fuel system pressure to make sure it is within the specified range. For additional information, refer to Specifications.
