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 relief valve
^ fuel pulse damper

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. Mechanical Returnless Fuel System (MRFS) operates at a constant 65 psi.

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.
^ should not be cleaned.

The fuel injectors:
^ are electrically operated by the PCM.
^ 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 supply manifold:
^ delivers fuel to the individual fuel injectors.
^ receives fuel from the fuel supply line.

The fuel pressure relief valve:
^ is used to relieve pressure from the fuel system.
^ is located on the fuel injection supply manifold.

The fuel pulse damper:
^ reduces pressure pulsations in the fuel injection supply manifold during fuel injector operation.