Civic L4-1.8L CNG (2008)
Fuel Pressure Release: Service and Repair
Fuel Pressure Relieving
WARNING: Compressed natural gas is flammable and highly explosive. You could be killed or seriously injured if leaking natural gas is
ignited.
Stop the engine, and keep heat, sparks and flames away.
This procedure should be done outside in a well-ventilated area or in a properly equipped CNG shop.
Between the engine and the manual shut-off valve
This procedure will allow you to safely work on any part of the fuel system downstream of the manual shut-off valve, such as fuel pressure regulator P1
or the fuel injectors.
1. Lift the vehicle, and support it with jackstands.
2. Close the manual shut-off valve (A).
3. Start the engine, and let it idle. After a few minutes, the engine will stall.
4. Turn the ignition switch OFF.
Between the fuel tank and the engine
This procedure will allow you to safely work on any part of the fuel system downstream of the fuel tank such as the fuel joint block or the manual
shut-off valve.
NOTE: Make sure the manual shut-off valve is open.
1. Remove the rear seat.
2. Disconnect the fuel subharness 6P connector (A) (this prevents the tank from supplying fuel to the system).
3. Start the engine, and let it idle. After a few minutes, the engine will stall.
4. Turn the ignition switch OFF.
Between the fuel receptacle and the fuel tank
This procedure will allow you to safely work on any part of the fuel system between the fuel joint block and fuel receptacle.
