Fuel Delivery System

Central SFI Fuel System With Fuel Pressure Gauge:

FUEL SYSTEM (OVERVIEW)
The fuel system is controlled by the control module located in the engine compartment. The control module is the control center of the system. The basic function of the fuel system is to control fuel delivery to the engine under all operating conditions. The fuel injection (Central SFI) delivers the fuel to the engine, and the fuel supply system supplies the fuel to the injection.

The main control sensor is the (Heated) Oxygen Sensor (HO2S). The HO2S is located in the exhaust manifold. The HO2S tells the control module the amount of oxygen in the exhaust gas. The control module changes the air to fuel ratio to the engine by controlling the fuel injector. Efficient catalytic converter operation requires a 14.7:1 air to fuel ratio. Because the constant measuring and adjusting of the air to fuel ratio, the fuel injection system is called a Closed Loop system.

Several other important engine operation parameters include the following items:

- The engine speed
- The manifold pressure
- The engine coolant temperature
- The throttle position

These parameters determine the mode of engine operation.

The following are the 2 separate classifications of the fuel system:

- The Central Sequential Fuel Injection (Central SFI)
- The fuel supply system

The engine performance specifications along with the controlled idle speed specifications are included for all engine applications.

FUEL SUPPLY COMPONENTS
The fuel supply is stored in the fuel tank. An electric fuel pump, located in the fuel tank with the gauge sending unit, pumps fuel through an in-line fuel filter to the fuel meter body assembly.

The pump provides fuel at a pressure greater than is needed by the injectors. The fuel pressure regulator, part of the fuel meter body assembly, keeps the fuel to the injectors at a regulated pressure. Unused fuel is returned to the fuel tank via a separate line.