Multipoint injection system MPI (Multipoint — Injection) (Audi 80 B3)

170 hp engines with the 7A designation are equipped with the so-called MPI injection system. MPI means that the injection moment and duration for each cylinder are calculated separately. In the MPI system, fuel injection and ignition are controlled by one common control unit. Each injection valve is under the same constant pressure. The injection valves are controlled by electromagnetic pulses from the control unit. The injection quantity for each cylinder is determined by the duration of the open state of the valve. The injection and ignition moment are calculated according to the characteristic stored in the control unit's memory based on an analysis of the speed, engine temperature, gas pedal position, load mode, and switching moment (for automatic transmission).

Special equipment is required to check the electronics of the MPI system. Checking and repair work should only be carried out in a specialized repair shop.

(The original source of the article can be found on the website: «audimanual.ru»)