Fuel is supplied through injectors, i.e. intermittently injected directly under the engine intake valves. The electronic engine control unit regulates the duration of the injector opening and, thus, the amount of fuel injected.
Air is drawn into the engine through the air filter and through the throttle valve fitting and intake manifold to the intake valves. The amount of incoming air is regulated by the throttle valve, which is controlled by the driver via the pedal and accelerator cable. The amount of incoming air is measured by the mass air flow sensor.
Information received by the electronic control unit from other sensors, as well as commands sent to the actuators or control mechanisms, ensure optimal engine operation in any situation that occurs while driving. If one or more main sensors fail, the electronic control unit runs an emergency program to reduce the risk to the engine and ensure continued driving. In such cases, the engine begins to run intermittently and may stall when the accelerator pedal is pressed.
The control unit recognizes and registers any faults that have occurred, creating an error log. When performing service work and during vehicle maintenance, workshops read and print out the entire list of registered faults using a diagnostic tester. If the vehicle owner suspects a fault in the fuel injection system, they can contact the workshop and receive a corresponding fault printout, as well as professional assistance in eliminating the defect. After the fault has been eliminated, it is deleted from the log.
Main sensors and actuators of the injection system:
- a) coolant temperature sensor:
- b) an accelerator pedal position sensor that informs the engine control unit of the current pedal position; based on the signals received, the control unit sets the throttle valve opening angle;
- c) the throttle position sensor transmits information about the angular position of the throttle valve to the electronic control unit;
- d) the idle speed controller determines the idle speed and ensures a constant speed regardless of the number of electrical consumers connected to the vehicle's electrical system, such as the rear window heater or the air conditioning compressor;
- d) the fuel pressure regulator maintains constant fuel pressure in the fuel rail;
- e) The intake air temperature sensor is used to determine the required volume of intake air;
- g) the camshaft position sensor transmits information to the control unit about the position of the piston of cylinder No.1 at TDC;
- c) the crankshaft position sensor determines the rotation speed and position of the crankshaft;
- k) the lambda probe regulates the composition of the exhaust gases, determining the oxygen content in them and transmitting the corresponding information to the control unit.