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 multiport, Sequential 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 plate.
- 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. Do not clean the fuel injectors.







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.
- 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.