What is MPFI, Port, TPI and Multi Point Fuel Injection?
[back] MULTI POINT or PORT FUEL INJECTION—MPFI (Multi Point Fuel Injection) uses an individual injector placed directly above the intake valve for each cylinder. This is the most commonly used type of system in today’s vehicles. MPFI allows full compliance with OBDII requirements and produces less HC emissions on cold engine start ups. These systems also eliminate most fuel distribution problems since the fuel is injected directly on top of the the intake valve, and not mixed prior to that point. One of the biggest advantages of MPFI is the flexibility of intake manifold designs. Most systems are designed with long intake runners, producing more low end engine torque, which is where most daily driving is done. This allows good camshaft grinds for idle stability while providing this drivability advantage. Some of the newer systems are designed with a long and short runner design. A communication valve is placed in the intake manifold that switches between long and short runner dependi
