Fuel injection and emission control systems are linked both structurally and functionally. For more information on these systems, see chapter 6.
Air supply system
The air supply system includes: air cleaner, air ducts, mass air flow sensor, throttle valve, idle control system and intake manifold. On V-engines, the intake manifold has a variable configuration, More information about the variable configuration manifold see chapter 6.
The throttle body is heated from below by engine coolant. This prevents it from freezing in cold weather. Throttle valve rotation is measured by a position sensor. To control engine idle speed, the throttle body has a valve to control the additional air flow directed around the throttle. On 4-cylinder engines, this valve is located on the upper side of the throttle body, and on a V-engine, on the lower side.
When the engine is idling, the desired composition of the working mixture is maintained by the idle control system. This system includes: electronic control unit (BEU), coolant temperature sensor, auxiliary air flow control valve and other sensors that provide information to the ECU. The idle control system takes into account the operating conditions of the engine, in particular, it takes into account the increase in engine load when additional consumers are turned on, such as an air conditioning compressor, steering pump, etc., as well as the engine operating temperature. The idle air valve controls the flow of air that bypasses the throttle and enters the intake manifold. To facilitate starting, when cranking the engine with the starter and immediately after starting, the idle air valve is fully open to supply the maximum amount of air.
Electronic control unit
Detailed information about the electronic engine management system is given in chapter 6.
Fuel injection system
The fuel injection system includes: fuel pump, pump relay, fuel pressure regulator, fuel rail and injectors.
The fuel pump, located in the fuel tank, delivers fuel through a full-flow filter to the fuel rail. A shut-off valve is installed at the outlet of the tank, which, when the pump stops, closes the fuel line and stores excess pressure in it. In addition, there is a bypass valve at the pump outlet, which does not allow increased fuel pressure in the delivery line. It opens at low fuel consumption by the engine or in case of blockage of the line and bypasses fuel from the pump outlet back to the inlet.
A fuel pressure regulator is installed in the fuel rail, which maintains a predetermined pressure at the fuel inlet to the injectors in any engine operating mode. Excess fuel from the pressure regulator is returned to the tank.
The injectors are electromagnetically controlled with a needle valve. When a control pulse is applied to the electromagnet from the BEU, the valve needle rises and through the opened molester, fuel under pressure from the ramp is injected into the inlet valve pipe of the next cylinder. The cyclic fuel supply is determined by the duration of the control electrical pulse.
The fuel pump relay is located in the relay box in the engine compartment.