Fuel Charging and Controls

Part 1:

Part 2:

The fuel injection supply manifold:
^ delivers fuel to the fuel injector.
^ receives fuel from the fuel supply line.
^ returns unused fuel to the fuel tank through the fuel return line.

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

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