Multi point fuel injection

this topic related with automobile engineering,it help to knowledge about mpfi system in engine.

1. Introduction In petrol vehicles carburetor is used for supplying air fuel mixture to the cylinder In response to the recent demand for cleaner exhaust emission improved drivability and mileage carburetor is not sufficient In place of the carburetor MPFI system is used in vehicles MPFI system is injects fuel into individual cylinders based on commands from engine control module The MPFI gives higher output, faster throttle response under varying driving conditions

2. History & Development Herbert Akroyd Stuart developed the first mpfi system The first use of direct gasoline injection was on the Hesselman engine invented by Swedish engineer Jonas Hesselman in 1925  One of the first commercial gasoline injection system  developed by Bosch and introduced in 1952 on the Goliath GP700 and Gutbrod Superior 600  

3. Basic Concept MPFI is an intelligent way of doing what a carburetor does. In this system each cylinder has injectors to spray the fuel/air charge into the cylinders. The fuel and air are mixed in what is called the intake manifold. In MPFI, each injector in controlled by the ECU(Electronic Control Unit)

4. The ECU monitors various engine parameters and accordingly decides just how much fuel is to be injected into the cylinder and at precisely what time . This system also allows each cylinder to be controlled independently

5. Components of MPFI The system has four major components they are Air intake system Fuel delivery system Electronic control system Emission control system

6. Type Of MPFI Systems The various types of MPFI systems are: 1. Simuntaneous : Together in all the cylinders. 2. Sequential : Direct injection into the individual cylinders against their power strokes. 3. Group : In cylinder pairs [in V engines]

7. Choosing the correct technique according to the engine configuration results in: - better power balance between cylinders - higher output from each cylinder - faster throttle response Of these technologies, sequential gives the best combination of power balance and output in inline 4 cylinder engines.

8. Advantages Of MPFI (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. (3) No need to crank the engine twice or thrice in case of cold starting as happens in the carburettor system.

9. (4) Immediate response, in case of sudden acceleration / deceleration. Since the engine is controlled by ECU, 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. (6) The mileage of the vehicle will be improved.