 printable version
Fuel Injection System - general information
System multipoint fuel injection (MPFI) consists of three subsystems: an air supply and electronic control of fuel supply. The system operates using the control module RSM complete with a variety of sensors (temperature sensor cooler, throttle position sensor (TPS), absolute pressure sensor in the pipeline (MAP), oxygen sensor, etc.), on the basis of which the transmitted information unit It defines the desired structure of the current air-fuel mixture (for the specific operating conditions of the car's systems). Locating components fuel injection system of the engine capacity 4.0 l Locating components fuel injection system of the engine capacity of 5.2 liters. The fuel injection system and the system of emission control and engine management are closely linked in the work and layout. For more information, see chap. Systems for reducing emissions and engine management. Supply system (intake air) The system consists of an air cleaner, the air intake hose, a throttle body, a control system is idling and the inlet conduit. Throttle Position Sensor (TPS) is fixed to the axis of the flap and transmits information about the current position of the flap. On models equipped with engine capacity of 5.2 liters of absolute pressure sensor in the pipeline (MAP) is set to the throttle, whereas in models with engine capacity of 4.0 liters it is fixed to the bulkhead of the engine compartment. When the engine is idling, the composition of the air-fuel mixture is controlled by a system of stabilization of turns of idling (IAC), which consists of a control module RSM and additional air valve (IAC). IAC valve includes a module (PCM), depending on the specific operating conditions of the engine (the operation of the air conditioning system hydrostrengthening steering, engine temperature, etc. conditions). The valve allows adjustment of the air flow over the throttle valve and the intake manifold. PCM receives information from various sensors (vehicle speed sensor (VSS), the coolant temperature sensor, sensor mode and start the air conditioner system hydrostrengthening steering, etc.) and adjusts the idling speed in accordance with the needs of the engine and driver. The electronic control system See chap. Systems of decrease in toxicity of the fulfilled gases and engine management. Fuel The system consists of the following components: a fuel pump, fuel pressure regulator, fuel injectors, injector resistor and the main switch. The fuel pump is mounted linear direct drive pump. Fuel is drawn through the filter into the pump passes through the anchor line one-way valve enters the second filter and is then fed to the injectors. The safety valve is used to prevent an excessive rise of pressure and opens in the case of locking the discharge side, allowing easy passage of the fuel from the high-pressure low-pressure system. The pressure regulator serves to maintain the fuel pressure at the injectors constant predetermined level. The excess fuel flow back to the fuel tank through the return line. Injectors - plunger type with permanent magnets act on the course. Injector composed of an electromagnet, a plunger, and a needle valve housing. When current supply to the solenoid electromagnet needle valve is lifted and fuel under pressure into the injector body and then through the nozzle is injected into the engine. The amount of fuel injected is determined by the length of time pulse valve opening (pulse width supplied to the electromagnet coil current). In view of the fact that it determines the opening and closing intervals of the injectors, which, in turn, determines the composition of the air-fuel mixture distribution moments actuation injectors must be set very precisely. To ensure the most effective operation of the front injector pulse current when voltage is applied to the solenoid of each injector should be as cool. Thus, the number of windings of the solenoid is minimized to reduce inductance. However, this leads to a decrease in the resistance of the solenoid, which reduces the service life of the injector. The current limiting resistor mounted in the injector wiring harness. The main relay, which is installed next to the fuse box assembly, the relay is direct connection, and provides power relay electronic control unit and the relay power supply to the fuel pump.
| 
