MPFI (Multi Point Fuel Injection)

MPFI Petrol Injectors with the fuel lines
IMG Ref: http://dieselpumpservice.com/services

MPFI means Multi Point Fuel Injection system. In this system each cylinder has number of injectors to supply/spray fuel in the cylinders as compared to one injector located centrally to supply/spray fuel in case of single point injection system. MPFI system injects fuel into individual cylinders after receiving command from the on board engine management system computer or Engine Control Unit (ECU).

Advantage of M. P. F. I.

1. More uniform A/F mixture will be supplied to each cylinder, hence the difference in power developed in each cylinder is minimum. Vibration from the engine equipped with this system is less, due to this the life of engine components is improved.
2. No need to crank the engine twice or thrice in case of cold starting as happens in the carburetor system.
3. Immediate response, in case of sudden acceleration / deceleration.
4. Since the engine is controlled by ECM* (Engine Control Module), more accurate amount of A/F mixture will be supplied and as a result complete combustion will take place. This leads to effective utilization of fuel supplied and hence low emission level.
5. The mileage of the vehicle will be improved.
   

ECM (Engine Control Module) and its function

The function of ECM is to receive signal from various sensors, manipulate the signals and send control signals to the actuators. Sensors; Sensing different parameters (Temperature, Pressure, Engine Speed etc.) of the engine and send signal to ECM. Actuators; Receives control signal from ECM and does function accordingly (ISCA, PCSV, Injectors, Power Transistor etc.)

Reference:

http://www.automobileindia.com/consumer-guide/automobile-technology.html