Fuel Charging and Controls

FUEL CHARGING AND CONTROLS

The fuel charging and controls system consists of the:
- throttle body.
- fuel injectors.
- fuel charging wiring.
- fuel pump driver module.
- fuel injection supply manifold
- fuel injector pressure and temperature sensor.

The fuel charging and controls system is:
- a sequential multiport fuel injection (SFI) system.
- pulse-width modulated.
- mass air flow controlled.

The powertrain control module (PCM) controls the fuel injection system. Injector pulse width is varied to control the amount of fuel flow through the injectors and into the engine. Varying fuel pump output controls fuel pressure. The PCM commands the fuel pump driver module, which directly controls the fuel pump.







The fuel injection supply manifold:
- delivers fuel to the individual fuel injectors.
- 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, speed control actuator cable to the throttle plate.
- is not adjustable.
- cannot be cleaned.

The fuel injectors:
- are electrically operated by the powertrain control module.
- have an internal solenoid which opens a needle valve to inject fuel into the lower intake manifold.
- atomize the fuel as it is delivered.
- are deposit-resistant.

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.

The fuel pump driver module:
- receives signals from the PCM.
- duty cycles the fuel pump.

The fuel pump relay engages the fuel pump when energized by the powertrain control module through the fuel pump driver module.