Fuel Injection System

Fuel Injection System

1. ECU.

2. FUEL INJECTORS.

3. OXYGEN SENSOR.

4. CATALYTIC CONVERTER.

The multi-point fuel injection (MPI) system supplies fuel to the engine under all operating conditions and modes. Fuel enters the

engine through injectors located in the intake manifold near each cylinder.

The main sensor for the MPI system is the oxygen sensor (O2 sensor) in the engine exhaust

gases. The O2 sensor is installed in the exhaust manifold.

Based on signals from the O2 sensor, the ECU determines the oxygen content in the exhaust

gases and controls the air-fuel mixture supplied to the engine. The optimal air-fuel ratio is 14.7:1,

which ensures the most efficient operation of the catalytic converter and the

lowest level of harmful exhaust emissions. Since the O2 sensor is included in the ECU feedback circuit, the air-fuel mixture control loop is closed, see fig. Closed-loop

fuel mixture control.