Multi port / point fuel injection in petrol engines |
Multi port fuel injection or commonly known as MPFI or PGM-FI is used in all the new petrol cars in India. It basically came about to help cars conform with the new emission norms that came into play. This technology though has been able to transform petrol engined cars, they way they act and well, react.
The multiport fuel injection technology is a direct development from the venturi carburetor. Basically, the venturi carburetor uses the difference in pressure around the venturi area to suck the fuel from the tank and mix with the air around it; the problem is that the metering is not very sound and at times can lead to excessive wastage of precious fuel. This along with the harmful emissions resulting from the wastage or poor combustion of fuel is what MPFI is here to curb, with the aid of the Engine control Module.
Well, so MPFI can quite simple be compared to the injection that you get from your family doctor; just that here a measured amount of petrol is injected into air using injectors and the multi port refers to the fact that injection occurs for all the ports.
If you own a 16 valve car, with 4 cylinders; its got 8 inlet and 8 exhaust ports. So, if injection takes place at each and every port individually using one injector per port; its multiport fuel injection.
If, the injetiors are 1 for every 2 ports, its multipoint fuel injection. Also, an outdated technology is single point fuel injection where one injector injects fuel into all the ports. |
![multipoint fuel injection schematic](javascript:openwin("largephoto.asp?imagename=mpfi.jpg&imagetitle=multipoint fuel injection system schematic"))
