Operation of the petrol injection system

The fuel from the fuel tank is sucked in by the electric fuel pump and flows through the fuel filter located under the bottom of the vehicle to the injection unit. The pressure regulator ensures that the pressure in the fuel system is kept constant at 2.7 bar.

Through electrically controlled injectors, fuel is injected in batches into the intake pipe just before the engine intake valves. The engine control unit controls the duration of injection and, accordingly, the amount of fuel injected. Fuel injection is performed sequentially, i.e. injection nozzles are controlled one at a time according to the firing order.

Combustion air is drawn in by the engine through the air filter and flows through the throttle body and through the air inlet pipe to the intake valves. The amount of air is controlled by the throttle, which is operated by the driver through the accelerator pedal («gas») and cable «gas». The amount of incoming air is measured by an air mass meter. The body of the flowmeter contains an electrically heated wire, which is cooled by the flow of incoming air. In order to keep the temperature of the heated wire constant, its filament current changes in accordance with the flow of incoming air. Depending on the fluctuations in the glow current, the control unit recognizes the load condition and accordingly regulates the amount of fuel injected.

The engine control unit is a small, very fast computer. It determines the optimum ignition timing, injection timing and the amount of fuel injected.

Information from various sensors and commands to actuators (actuators) provide optimal engine performance in every situation. If a sensor fails, then the control unit switches to emergency mode to prevent damage to the engine and be able to move on. In this case, the engine can work! worse when applying «gas» he can choke.