The MPI system functions to control the air/fuel mixture to the optimum ratio. The various engine operating conditions are determined at the ECU according to signals input from various sensors, as a result of this information, the fuel injectors (one for each cylinder) are controlled according to driving conditions.
The injectors inject fuel to each manifold port, in the sequential firing order of each cylinder. The air/fuel ratio control is determined by the injection time of each injector as controlled by the ECU. During the start (cranking) process, there are two fuel injections simultaneously for each of the four cylinders.