Fuel Shut-off Solenoid: Description and Operation

NATURAL GAS FUEL SYSTEM

Fuel Rail Shut-Off Valve

Fuel Rail Shut-Off Valve:

The fuel rail shut-off valve (Figure 86) is a normally closed solenoid actuated valve that opens when (along with all of the tank valves) Pin 80 is grounded by the PCM. The valve isolates the fuel injectors from fuel line pressure when the engine is off. Nominal resistance of the coil is 11 ohms. The fuel rail shut-off valve is wired in parallel with the four tank valves.

Fuel Rail Valve Circuit Operation
When the key is turned to the ON position, the power relay is turned on. The power relay provides power to the PCM and the control side of the fuel shut off valve relay. The relay provides voltage to the fuel rail valve. If the ignition switch is not turned to the START position, the PCM will shut off the fuel rail valve after one second. The PCM will open the valve (along with the four tank valves) to provide fuel while cranking. The valve will remain open when the engine is running unless the inertia fuel shut-off switch is "tripped."