Fuel Delivery and Air Induction: Description and Operation

OPERATION
The fuel system consists of electronic fuel injectors, electric fuel pump, fuel rail, fuel pressure regulator and the Engine Control Module (ECM). The ECM controls all the electronic components according to the memory maps in the ECM. The Fuel Injectors are mounted to the Fuel Rail. Fuel pressure in the Fuel Rail is regulated to a constant pressure by a Fuel Pressure Regulator mounted to the downstream end of the Fuel Rail. Fuel Injectors, one for each cylinder, are triggered sequintially at a rate that is proportional to engine rpm. Fuel mixture is controlled by the length of time that the Fuel Injectors stay open. The ECM controls the injection duration by switching the ground circut for each injector, the injector have a constant power supply.

MIXTURE CONTROL
The fuel mixture is monitored by the use of two oxygen sensors, one for each bank of cylinders. The ECM can control fuel mixture for each bank of cylinders separately based on Oxygen Sensor signal, Coolant Temperature Sensor signal, and the Mass Air Flow Sensor signal as its primary input signals. The ECM then adjusts the injection duration to obtain the proper fuel mixture for the current operating conditions.

FUEL SYSTEM COMPONENTS
These components are related to fuel and air delivery portion of the engine control system.

^ Fuel Injector
^ Fuel Pump
^ Fuel Pump Relay
^ Fuel Return Lines
^ Fuel Supply Lines
^ Fuel Rail
^ Fuel Pressure Regulator
^ Fuel Tank