Audi 80/Avant (B4)
since 1991-1995 release
Repair and operation of the car
+ Technical specification
+ System of production of the fulfilled gases
+ Cooling system
+ Fuel tank and fuel pump
+ Air filter and airintaking channels
- System of injection
- System of injection Mono-Motronic
Malfunctions and independent diagnostics
Check of separate elements
Check of the mode of idling and analysis of exhaust gases
Check of catalytic converter and lambda probe
Hummock drive of "gas"
List of malfunctions
+ System of injection Digifant
+ System of injection KE-III-Jetronic
+ Systems of injection of MPI and MPFI
+ Transmission and transmission
+ Suspension bracket and steering
+ Brake system
+ Anti-blocking system of brakes
+ Wheels and tires
+ Body electrical system
+ System of ignition
+ Signaling devices
+ Devices and auxiliary devices
+ Heating and ventilation
+ Body elements
+ Search of malfunctions
System of injection Mono-Motronic
Function chart of system of injection of Mono-Motronic
Central injectionThe smallest Audi engine is equipped with system of injection of gasoline through one nozzle and a butterfly valve, the so-called Mono-Motronic system. It consists generally of the case similar to the case of the carburetor and supplied with the one and only vpryskny nozzle. A fuel exit from a nozzle is regulated by an electronic control unit which at the same time provides management of regulation of an advancing of ignition.
It is located in legs of the forward passenger in front of the heating channel and via the multicontact plug obtains information from the following knots:
Processing the entering signals the control unit counts duration of opening of a vpryskny nozzle with the electromagnetic drive and by that amount of injectable fuel. At the same time the control unit uses multiparameter characteristics of the engine – the file in which all possible conditions of the engine are written down. In the same place in the form of electric signals the data on amounts of fuel relating to this or that situation are written down. In addition in the form of characteristics in Mono-Motronic the indicators of the moments of ignition relating to amount of fuel and an operational situation are kept.
It is located at the very bottom of the block of preparation of gas mixture and regulates amount of air which the engine has to receive.
Block of preparation of gas mixture
The majority of details of the central system of injection of gasoline are collected in this case. Through it there passes the arriving air, and here – by means of a nozzle – fuel, as well as in the carburetor is added.
It opens by means of an electromagnet. Thus fuel can arrive – or not – depending on a signal from the control unit. For optimum dispersion of fuel the nozzle is supplied with slanted outlets via which gasoline gets on a conic wall of the outlet, swirling there.
The sensor of temperature of the arriving air
It is located sideways on the case of a nozzle and thus can precisely determine air temperature, the preparation of gas mixture coming to the block.
The fuel pump under pressure gives gasoline to pressure regulator which provides intake of gasoline to a nozzle under the same pressure of 0,8 - 1,2 bars. For this purpose he allows a most or smaller part of gasoline to go back to the fuel tank on the drain highway. Giving via the fuel filter remains almost constant.
Regulator of provision of a butterfly valve
The small electric motor with angular transfer moves a driving pusher closer or farther from an emphasis of idling of a butterfly valve. Thus, depending on a situation the butterfly valve can open at a big or smaller size.
Potentiometer of a butterfly valve
He reports to the control unit about the movements of a butterfly valve and its situation. So, for example, bystry opening of a butterfly valve is distinguished as acceleration of the car. If you take away a leg from an accelerator pedal, then the signal of closing of a butterfly valve activates interruption in supply of fuel in the idling mode. The message passes in a type of an electric signal – the potentiometer represents not that other as variable resistance.