Audi 100/A6

1990-1997 of release

Repair and car operation

6.3.3. Distinctions of systems of injection

THE GENERAL DATA

The system of injection MPI has a switched inlet collector, two-piece whereas system MPFI is equipped by not switched plastic inlet collector consisting of three parts. Besides, the measuring instrument of the mass expense of air any more is not required to system MPFI.

Fuel is soaked up from a fuel tank by the electric pump and through the fuel filter moves to дозатору which is executed in the form of ring топливопровода, and then to клапанным to atomizers. The pressure regulator on the end дозатора supports to constants pressure of fuel in system.

Klapannye atomizers consistently inject fuel into an inlet collector in front of inlet valves. Injection is carried out not simultaneously. It means that atomizers are separated, cope separately and inject fuel according to sequence of flashes in front of inlet valves of the engine. Thanks to a choice of the beginning of injection in relation to the moments of opening of inlet valves can be regulated is better мощностные and ecological qualities of the engine. Besides, improves приемистость the engine.

Unlike system of injection KE in system MPI instead of a measuring instrument of the volume expense the measuring instrument of the mass expense of air is built in. Such measuring instrument has following advantages: insignificant dimensions, automatic alignment of influence of temperature and height above sea level, absence of mobile details and consequently insignificant deterioration.
In a measuring instrument of the mass expense нагретая an electric current the thread is cooled by a stream of soaked up air proceeding by. To maintain temperature of a hot thread of a constant, the heat current changes according to proceeding quantity of air. On change of a current of heat the management block defines a loading mode of the engine and according to it regulates quantity of injected fuel. To avoid distortion owing to pollution, after each deenergizing of the engine the thread is heated automatically.

The management block according to a signal of a measuring instrument of the mass expense of air and frequency of rotation of a cranked shaft regulates duration of injection, and thereby and quantity of injected fuel. At longer opening клапанной fuel atomizers it is injected more. Additional gauges and converters in any road situation care about correct отмеривании quantities of injected fuel.