F 150 Super Crew 4WD V8-5.4L Prop SOHC VIN Z (2003)
Fuel Cut Valve Solenoid (CNG): Description and Operation
Description and Operation (CNG)
NATURAL GAS FUEL SYSTEM
Fuel Tank Shutoff Valve
Fuel Tank Shutoff Valve
The fuel tank shutoff solenoid valve (Figure 84) is located in the fuel tank. The solenoid valves are on the same circuit as the gasoline fuel
pump and utilize the same Inertia fuel shutoff (IFS) switch as gasoline. When the key is in the off position, the shutoff valves are closed and
fuel in the tanks is isolated. During refueling, the shutoff valve acts as a check valve and allows flow due to pressure differential between the
fuel being added from the fill station and the fuel in the tank.
The internal solenoid valves also have the capability of being "manually locked down." If, while servicing the vehicle, it becomes necessary to
remove the fuel tank, the lock down feature provides an added measure of safety. In addition, the valve has an internal Canadian Gas
Association (CGA) type 9 fusible link Pressure Relief Device (PRD) that senses the internal fuel tank gas temperature. The contents in the
tank are vented when the internal fuel tank gas temperature reaches 199°C (217°F) and melts the fusible link. The escaping gas is vented
through a vent line to the atmosphere.
