Fuel Charging and Controls

Part 1:

Part 2:

The fuel shut-off solenoid:
^ is normally closed.
^ opens when the key is in the RUN or START position.
^ shuts off the fuel supply if the vehicle is shut off or if the inertia fuel shut-off is triggered.

The throttle body:
^ controls air supply to the upper intake manifold by positioning the throttle plate.
^ connects the accelerator cable and, if equipped the speed control actuator cable to the throttle plate.
^ is not adjustable.
^ cannot be cleaned.

The fuel injector:
^ uses the replacement O-rings if needed.
^ is electrically operated by the Powertrain Control Module (PCM).
^ has an internal solenoid that opens a needle valve to inject fuel into the lower intake manifold.
^ atomizes the fuel as the fuel is delivered.
^ is deposit resistant.

The fuel pressure relief valve:
^ is used to inspect and relieve fuel pressure.

The fuel pressure regulator:

CAUTION: Use O-rings that are made of special fuel-resistant material. Use of ordinary O-rings can cause the fuel system to leak. Do not reuse O-rings.

^ maintains a constant fuel pressure throughout the fuel system and to the fuel injector.
^ is spring-loaded and operated by the intake manifold vacuum.

The fuel injection supply manifold:
^ delivers fuel to the fuel injector.
^ receives fuel from the fuel supply line.
^ provides mounting surfaces for the fuel temperature sensor and the fuel pressure sensor.
^ provides mounting surface for the main fuel shut-off solenoid.

Fuel System Service Precautions

WARNING:
^ DO NOT MODIFY SYSTEM CONFIGURATION OR COMPONENTS OR INSTALL NEW COMPONENTS WITH PARTS NOT ESPECIALLY DESIGNED FOR USE WITH NATURAL GAS. FORD MOTOR COMPANY HAS SPECIALLY DESIGNED THE MATERIALS, COMPONENTS AND SYSTEM CONFIGURATION FOR THE NATURAL GAS VEHICLES AND EACH PARTICULAR SYSTEM IS PRECISELY CALIBRATED FOR EFFICIENT OPERATION. THE USE OF DIFFERENT PARTS OR MATERIALS CAN PRODUCE AN UNTESTED CONFIGURATION THAT CAN RESULT IN FIRE OR CAUSE ENGINE DAMAGE. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.
^ IT IS IMPORTANT THAT YOUR NATURAL GAS VEHICLE BE PROPERLY MAINTAINED BY FORD NATURAL GAS TRAINED PERSONNEL. IF A PROBLEM OCCURS, IT IS IMPORTANT THAT PROPERLY TRAINED PERSONNEL DIAGNOSE THE CAUSE. IF THE PROBLEM RELATES TO THE FUEL SYSTEM, PROPER PART REPLACEMENT IS IMPERATIVE TO KEEP THE VEHICLE OPERATING AT NORMAL PERFORMANCE. NATURAL GAS COMPONENTS AND GASOLINE FUEL COMPONENTS ARE NOT INTERCHANGEABLE. IF THE VEHICLE IS NOT SERVICED IN ACCORDANCE WITH NATURAL GAS FUELED VEHICLE PROCEDURES, DAMAGE CAN OCCUR AND THE WARRANTY MAY BE INVALIDATED. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.
^ FUEL SUPPLY LINES ARE ALWAYS PRESSURIZED. WHEN SERVICING FUEL-RELATED COMPONENTS, DO NOT SMOKE OR CARRY LIGHTED TOBACCO OR AN OPEN FLAME OF ANY TYPE. FLAMMABLE MIXTURES MAY BE PRESENT AND CAN IGNITE. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.
^ THE FUEL SYSTEM IS ALWAYS PRESSURIZED TO 655 KPA (95 PSIG) DOWNSTREAM OF THE FUEL PRESSURE REGULATOR AND UP TO 20700 KPA (3000 PSIG) UPSTREAM OF THE FUEL PRESSURE REGULATOR. USE CARE WHEN SERVICING THE FUEL SYSTEM. FUEL PRESSURE MUST BE RELIEVED PRIOR TO ANY FUEL SYSTEM SERVICE. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.