Federal

Fuel Control System (Federal):

General Description
The fuel injection system delivers a precise amount of highly atomized fuel to the intake system to ensure optimum performance and emissions compliance.

The Fuel System consists of three major sub-systems:
- The fuel storage system,
- Fuel injectors with the supporting fuel injection control system, and
- The fuel delivery and return system.

Fuel Storage
The fuel storage system consists of a fuel tank, fill spout and filler cap.

Fuel Injection and Control
The Injectors are solenoid operated valves designed to deliver fuel in an appropriate spray pattern to promote total fuel atomization in the intake air stream

The Fuel Injection Control System consists of the ECU (Electronic Control Unit) and all of the engine and operating condition sensors. Using the information from the sensors to determine the proper fuel amount and delivery time, the ECU varies the injectors "ON" time to adjust the amount of fuel delivered during each individual firing cycle.

For a more detailed description of the fuel injection system operation, refer to COMPUTERIZED ENGINE CONTROLS. For all Fuel System mechanical component descriptions, refer to this section by component name.

Fuel Delivery and Return
The fuel delivery system delivers fuel at a pressure and quantity high enough to allow the fuel regulator to maintain a constant fuel pressure in the fuel delivery rail (in reference to the intake manifold pressure) under all driving conditions. A check valve in the fuel pump holds pressure in the system after engine shutdown to prevent vapor lock and to ensure adequate pressure is available during warm engine START conditions.

The fuel delivery components consist of fuel supply lines, a high pressure fuel pump (mounted in the fuel tank), a fuel filter assembly, a fuel pressure accumulator and a fuel pressure regulator.

The fuel return system recovers excess fuel vented by the fuel pressure regulator (mounted on the fuel rail) and returns it to the fuel tank. The fuel return line is low pressure and returns directly to the fuel tank. The fuel return system consist of lines and couplings and therefore is addressed, jointly with the fuel supply lines, under the heading of FUEL/VAPOR LINES.

The fuel vapor recovery system provides a route for the recovery of fuel vapors (from the fuel tank) either for storage in the charcoal canister, or for evacuation through the purge control system. The vapor recovery system also consists of lines and couplings addressed under the heading of FUEL/VAPOR LINES in this section. Additionally contained in the vapor recovery system are two components, an overfill limiter and a fuel check valve. These components function as evaporative emissions control devices and are therefore covered in detail in EMISSION CONTROLS.