Fuel Charging and Controls

The fuel charging and controls system consists of the:
^ throttle body
^ fuel injectors
^ fuel charging wiring
^ fuel injection supply manifold
^ fuel pressure regulator
^ fuel pressure relief valve
^ A/C compressor clutch relay
^ fuel pump relay

The fuel charging and controls system is:
^ a Sequential Multiport Fuel Injection (SFI) system.
^ pulse width modulated.
^ mass air flow controlled.

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, 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).
^ each have an internal solenoid which opens a needle valve to inject fuel into the lower intake manifold.
^ atomize the fuel as the fuel is delivered.
^ are deposit-resistant.

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

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

The A/C compressor clutch control relay (if A/C equipped):
^ is controlled by the powertrain control module (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.