MPFI stands for Multi Point Fuel Injection. In this system fuel is injected into the intake ports which is situated just upstream of each cylinder’s intake valve. These systems are sequential systems, in which injection is timed to coincide with intake stroke of each cylinder.

TPFC stands for transient power fuel control system. In this type of systems constant choke carburetor is used. The salient feature of this carburetor is that it provides jerk less engine raise. In these systems, throttle valve creates vacuum which opens the slide which controls the air fuel ratio through a tapered jet.