Fuel Charging and Controls

The fuel injection supply manifold:

• Delivers fuel to the individual fuel injector.
• Receives fuel from the fuel supply 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 pulse damper:

• 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.

Refer to the INTRODUCTION - CNG, FLEX-FUEL & GASOLINE article.