Meanwhile, the control diaphragm and pressure spring control the inlet valve opening and the amount of fuel that can return. The fuel pressure regulator is connected to the fuel rail and governs the fuel flow. In the system, multiple fuel injectors are situated upstream of the cylinders’ intake valves. As every cylinder has a specific injector, there is a negligible possibility of fuel condensation outside the intake manifold. These fuel injectors inject an optimum quantity of fuel into the combustion chamber, which also results in better atomization and swirl of fuel in the combustion chamber.

In multi-point fuel injection (MPFI) technology, every cylinder in the combustion chamber of the engine is given an injector at the front of their inlet valves (outside the intake port), which is why it’s also called ‘Port Injection’.

Due to the absence of electronic control, a carburettor cannot properly measure the air-fuel ratio with changing air pressure and fuel temperature Image Courtesy: LEARN AND GROW The carburettors mix the air-fuel in the required ratio, and supply it to the intake manifold. How Does the MPFI System work?īefore MPFI let’s learn a bit about carburettors. In this article, we learn what MPFIs are and how they function. The multi point fuel injection system is one of the best engineering marvels ever produced, and today, every petrol and CNG car, irrespective of its price, comes with MPFI.

While carburettors used to do this duty until the mid-90s, it was in the late 90s when multi point fuel injection systems made their way to the Indian market, and then rapidly popularised themselves for their best efficiency. By all odds, the engine is the most important part of any car, and its life very much depends upon the way fuel is supplied to it.

Sequential electronic fuel injection