An EFI vehicle refers to a vehicle equipped with an electronically controlled fuel injection system and using an EFI engine. EFI is the abbreviation of "electronically controlled gasoline injection engine"; Gasoline injection is to spray gasoline into the intake manifold, air intake or cylinder in a mist at low pressure (260~350kPa), and then mix with air to form a combustible mixture.
The electronically controlled gasoline injection system uses the sensors in the system to convert the monitoring parameters of the engine running state (such as air flow, engine speed, intake pressure, intake temperature, coolant temperature, oxygen content in exhaust gas, etc.) into electrical signals, which are input to the engine controller (ECU, also known as electronic control unit). According to these signals, the controller calculates the fuel injector (the structure of the fuel injector is solenoid valve, which starts fuel injection when the solenoid valve is energized, and the energization time determines the fuel injection quantity), and connects the fuel injector circuit to make the fuel injector inject fuel, thus accurately controlling the fuel injection time and fuel injection quantity of the fuel injector. ECU can also accurately control the ignition advance angle of the engine according to the signals sent by various sensors.