Fuel Charging and Controls

The fuel injection supply manifold:
^ delivers fuel to the individual fuel injectors.
^ 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 lever.
^ is not adjustable.
^ cannot be cleaned.

The fuel injectors:
^ are electrically operated by the Powertrain Control Module (PCM).
^ atomize the fuel as the fuel is delivered.
^ are deposit-resistant.
^ each have an internal solenoid that opens a needle valve to inject fuel into the lower intake manifold.

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

The fuel pressure regulator:
^ maintains constant fuel pressure throughout the fuel system and to the fuel injectors.
^ is spring-loaded and operated by intake manifold vacuum.

The A/C compressor clutch control relay (if A/C equipped):
^ is controlled by the PCM.
^ interrupts A/C clutch operation during engine start or manual transmission clutch engagement to reduce engine load.

The fuel pump relay engages the fuel pump when energized by the PCM.