Computers and Control Systems: Description and Operation

MPI SYSTEM DIAGRAM

GENERAL INFORMATION
The MPI (Multi-Point Injection) system controls the Fuel flow, idle speed, and ignition timing. The basic function of the MPI system is to control the air-fuel ratio according to operational conditions through the Electronic Control Unit (ECU), based on data from various sensors. The MPI System is roughly divided into three areas such as the fuel system, intake system, and control system.

CONTROL SYSTEM
The control system is composed of a sensor section, which monitors engine conditions, and an Electronic Control Unit (ECU), which calculates the injection timing and rate according to the signals from the sensors. The sensors convert such conditions as the amount of intake air, amount of oxygen in the exhaust gas, coolant temperature, intake air temperature, engine revolution speed, and driving speed into electric signals, which are sent to the ECU.
Analyzing these signals, the ECU determines the amount of fuel to inject according to driving conditions and drives the injectors. The fuel injection is by sequential injection type, in which six injectors are sequentially driven.
During idling, the SC Servo is driven according to the load to assure stable idling.