American Motors: MPFI, coolant temperature, fuel mileage


Question
what actually is MPFi and what is the difference between it and the conventional form of injection  thru Carburettor

Answer
MPFI is Multi Point Fuel Injection. The computer controled system consists of a fuel injector for each cylinder, usually located in the intake manifold. The injector is an electronic solenoid that is turned off and on (injector pulse) by the computer. It injects fuel under pressure into the air stream going into each cylinder. The computer (ECM) controls the injector pulse based on numerous engine inputs such as coolant temperature, engine RPM, Volume of air coming into the engine, throttle position, amount of Oxygen in the exhaust, and many more. This precise control of the injectors allows for better fuel mileage, lower emmisions, better performance, and fewer mechanical parts. A carburetor, a mechanical device, mixes fuel with air that is introduced into the engine depending on where the throttle is and engine load. Though it has been improved through the years, it is not easily controled by a computer.
With today's emission requirements and cost of gas, fuel injection is the way to go.Hope this helps.