Working priciple of MPFI

• The MPFI is an advanced version of the carburettor engine. MPFI full meaning is a multi-point fuel injection system.
• Even though the working of MPFI engine is somewhat similar to the engine used by carburettor each cylinder is treated individually. 
• A separate injector supplies the correct quantity of fuel to each of the engine cylinders by a fuel-rail according to the firing order or in a particular sequence. This system provides further precision by varying the fuel quantity and injection timing by governing each injector separately and thereby improving the performance and controlling the emissions.
• The return valve returns fuel in case the fuel is oversupplied. Also, the pressure regulator regulates the pressure of the intake of  fuel. Fuel filter contains small-sized membranes which filter and absorbs undesirable matters of size 30 to 40 microns.
• The fuel and air are mixed in the intake manifold and each manifold is controlled by an ECU(Electronic Control Unit). fuel pressure runs between 3 to 5 bars.