The amount of fuel supplied to the fuel injectors is controlled by the engine control unit (ECU). The ECU receives signals from the crankshaft angle sensor and the camshaft position sensor and ensures that fuel is supplied to the fuel injector in the firing sequence of the engine cylinders, which improves fuel economy and reduces harmful emissions in the exhaust gases. The ECU controls the fuel injection system, ignition and exhaust emissions. All information coming to the ECU is compared with preset values stored in the ECU memory and determines the required fuel injection period. Information regarding the engine speed comes from the crankshaft angle sensor. This is an inductive pulse generator that determines the passage of ridges between 36 holes located on the inner side of the flywheel. As each ridge passes the sensor, a signal is induced which is used by the ECU to determine the crankshaft speed. The ridge between holes 35 and 36 is missing and, based on the absence of a sensor signal, the ECU determines the position of the crankshaft.
The camshaft position sensor is located on the RTE, Zetec and Zetec-E engines in the cylinder head and is controlled by a lobe on the camshaft. On Endura-E engines, the sensor is located on the chain cover and is controlled by a rotor plate bolted to the camshaft sprocket. The camshaft position sensor works in the same way as the crankshaft angle sensor, generating a series of pulses that allows the ECU to determine the firing order of the cylinders and open the fuel injectors in the appropriate sequence.
The mass air flow sensor is a live wire that sends out a constantly changing voltage signal corresponding to the mass of air flowing into the engine.
To determine the engine temperature, a sensor is used, which is a thermistor, i.e. a semiconductor whose electrical resistance decreases as the temperature increases. This signal is used to determine the optimal fuel mixture composition at a certain engine temperature. Information about the temperature of the incoming air is determined by a sensor, which is a thermistor with a negative temperature coefficient. This information is also used by the ECU to determine the optimal fuel mixture at a certain air temperature.
The throttle position sensor is mounted on the end of the throttle shaft and supplies the ECU with a constantly changing signal corresponding to the amount of throttle opening.
The vehicle speed is determined by a speed sensor, which is mounted on the gearbox speedometer drive. The sensor generates a series of pulses corresponding to the vehicle speed, allowing the ECU to adjust the amount of fuel supplied by the fuel injectors and also transmits information to the on-board computer and cruise control systems. If the vehicle is equipped with a power steering drive, a power steering fluid pressure sensor is used.
The oxygen sensor installed in the exhaust system provides constant feedback that allows you to adjust the fuel mixture for normal operation of the catalytic converter. The air supply system consists of an air filter housing, a mass air flow sensor, an inlet hose, tubes and a throttle body. The throttle valve, located inside the throttle body, is controlled by the driver from the accelerator pedal. When the throttle valve opens, the amount of air passing through the system increases, and the signal from the air flow sensor changes, causing the ECU to open each fuel injector for a longer time. As a result, the amount of fuel supplied to the engine increases. Idle speed and mixture quality are controlled by the ECU and cannot be adjusted manually. Checking the idle speed and fuel mixture quality can only be done using special diagnostic equipment at a service station.
Caution. The fuel system is under pressure even after the engine is turned off. Therefore, when performing any work on the fuel system, it is necessary to depressurize it and relieve the pressure.
The text was obtained in its entirety from the specified website (fordbook.ru)