Units of the electronic fuel injection system of 4-cylinder engines
1. Crankcase ventilation spool; 2. Fuel distributor and nozzle; 3. Throttle angle sensor; 4. Recirculation sensor; 5. Leveling chamber; 6. Diagnostic connector; 7. Mounting block; 8. Pneumatic shock absorber; 9. Fuel pressure regulator; 10. Air filter; 11. Flow rate sensor
Units of the electronic fuel injection system of V6 engines 3.4 l
1. Air filter; 2. Flow rate sensor; 3. Throttle angle sensor; 4. Recirculation sensor (under the equalization chamber); 5. Leveling chamber; 6. Fuel pressure regulator; 7. Diagnostic connector; 8. Mounting block
Vehicles equipped with an electronic fuel injection system (EFI system), which includes three subsystems:
- fuel system;
- air intake system;
- electronic control system.
Fuel system
The fuel pump, located in the tank, supplies fuel at a constant pressure to the distributor, from which the fuel is evenly distributed to the injectors. From the distributor, fuel is supplied to the inlet channels of the cylinders through the nozzles. The amount of injected fuel is strictly controlled by the electronic control unit (ECM block). The fuel pressure regulator ensures that the fuel pressure changes in accordance with the negative pressure on the intake manifold.
Air intake system
The air intake system consists of an air filter, a throttle chamber and a duct connecting these two units. Air temperature sensor (IAT sensor) monitors the temperature of the intake air. The signal from the sensor is sent to the electronic control unit, which provides the dosage of injected fuel in accordance with the air temperature. The throttle is controlled by the driver. As the throttle valve opens, the speed of the incoming air increases, which leads to a decrease in its temperature. The sensor registers the change in air temperature and sends a signal to the ECM, which in turn sends a signal to the injectors.
Electronic control unit (ECM block)
Control of electronic fuel injection and other systems is provided by the processor unit. The block includes a microcomputer. The control unit receives signals from a number of sensors that monitor such parameters as the temperature of the air at the inlet to the cylinders, the throttle angle, etc. Based on these data, the control unit determines the duration of fuel injection, which ensures that the optimal ratio of gasoline and air is maintained in combustible mixture.