Pic. 2.47. EFI system diagram (Electronic fuel injection system)
L type electronic fuel injection system (pic. 2.47) directly detects the intake air mass using hot-wire type air mass sensor. Adopts independent injection system (in which fuel is injected into each cylinder once every two revolutions of the crankshaft). In addition, group injection is used when starting the engine (fuel is injected once into two cylinders for every revolution of the crankshaft). There are two modes of operation of the fuel injection system:
- a) synchronous injection, in which the basic injection duration is adjusted according to the signals of the sensors so that fuel injection always occurs at a certain position of the crankshaft;
- b) asynchronous injection, in which fuel is injected when requests are detected by sensor signals, regardless of the angle of rotation of the crankshaft.
In addition, to protect the engine and improve fuel economy, the system performs a fuel cut, which stops fuel injection temporarily according to driving conditions.