Fuel Charging and Controls

The fuel rail:

• delivers fuel to the fuel injector.
• receives fuel from the fuel supply tube.

The throttle body:

• controls air supply to the upper intake manifold by positioning the throttle plate.
• is coolant heated.
• is not adjustable.
• cannot be cleaned.

The fuel injector:

• 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 injection pressure and temperature sensor:

• measures the pressure and temperature of the fuel in the fuel supply manifold and sends these signals to the PCM.
• uses intake manifold vacuum as a pressure reference.