The fuel injection system is in direct interaction with the engine management system. For more information, please see chapter 6.
Air intake subsystem
The elements of this subsystem include the air cleaner, intake air ducts, throttle body and intake manifold.
When the engine is idling, the composition of the fuel-air mixture is controlled by the idle air supply system. This system includes the PCM unit and the valve through which air enters in this mode. This system is used to control the air flow behind the throttle valve, which enters the intake manifold, due to which the engine speed increases or decreases in this mode. The PCM unit receives pulses from sensors (vehicle speed sensor, coolant temperature, air conditioning system activation, power steering mode, etc.), and based on these signals, the engine speed is automatically adjusted depending on its operating mode and the driver's actions. The design and operating principle of the air valve of the idle speed maintenance system are described in chapter 6.
Emission Control and Engine Management System
These systems are described in chapter 6.
Fuel supply subsystem
This subsystem consists of the following elements: fuel pump, fuel pressure regulator, fuel receiver and injectors.
The fuel pump has an electric drive. Through the fuel intake, gasoline enters the pump, passes through the shut-off valve, enters the fuel filter and is supplied to the fuel receiver and injectors. Constant pressure in the injectors is maintained by the presence of a fuel pressure regulator. From the regulator, excess gasoline is directed back to the tank via the fuel return line.
The solenoid type needle injector body contains a solenoid valve, a plunger and a needle valve. When voltage is applied to the solenoid valve winding, the needle valve is raised and fuel is sprayed under pressure from the tip. The amount of fuel injected is determined by the period of lifting of the needle (the period of voltage supply to the solenoid valve winding).
The fuel pump relay is located in the distribution block, which is located in the engine compartment. The PCM sends pulses to the relay coil, and the fuel pump is turned on. If the PCM does NOT receive signals from the camshaft or crankshaft position sensor (when the engine does not work and does not start), then the fuel pump relay is switched off.
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