Audi 80/Avant (B4)
since 1991-1995 of release
Repair and car operation
+ Technical specification
+ System of production of the fulfilled gases
+ cooling System
+ Fuel tank and fuel pump
+ Air filter and airintaking channels
- Injection system
+ System of injection of Mono-Motronic
+ System of injection of Digifant
- System of injection of KE-III-Jetronic
Malfunctions and independent diagnostics
Check of separate elements
Search of malfunctions
Removal of components
Check of a mode of idling and analysis of exhaust gases
List of malfunctions
+ 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 electrosystem
+ ignition System
+ Signalling devices
+ Devices and auxiliary devices
+ Heating and ventilation
+ body Elements
+ Search of malfunctions
Scheme of action of system of injection of KE-III-Jetronic. Red the fuel is shown, arriving air is allocated with the light pink.
Look on the proof-reader of composition of gas mixture of system of injection of KE-III-Jetronic
For the best understanding of complete functioning of our system of injection for a start it is necessary to explain the major details and concepts:
In a final collector in a branch pipe there are two butterfly valves. Smaller from these a zaslonok it is connected by a cable of a drive of "gas" with a pedal in salon. It doses out a stream of inlet air in the engine. If the pedal of an accelerator is squeezed out more strongly, draft opens the second, big zaslonka. In the provision of full "gas" both zaslonka are open.
Proof-reader of composition of gas mixture
It represents the main component of system of injection and consists of a flowmeter of air and the fuel batcher. They act so:
Pressure in system
The fuel pump in a fuel tank pumps over fuel under pressure in injection system. The first instance here is the regulator of system pressure in the separate case. It reduces an elevated pressure and leaves for fuel system only from 6,1 to 6,5 bar. This pressure, pressure in system, operates in the batcher, топливопроводе and vpryskny nozzles.
The regulator of pressure is responsible for mix structure. It occurs as follows: intake of fuel to the bottom chambers (through which it is possible to affect quantity of a mix) occurs through a pressure regulator. If it passes a lot of fuel in the bottom chambers, pressure increases in the bottom chambers. Consequence: membranes of so-called valves of pressure differences cave in towards klapanny openings – towards vpryskny nozzles less fuel gets. On the contrary it, of course, operates in the same way.
The regulator of pressure receives commands from the control unit. It occurs depending on a lambda regulation, temperatures of the engine and load of it.
Vprysknye of a nozzle
As soon as pressure of fuel reached 4,3 — 4,6 bar, nozzles submit gasoline to the canal in front of the valve of the corresponding cylinder. Thus they open to 2000 times a second thanks to what gasoline is sprayed is especially thin.
The control unit regulates structure of a mix of the engine through a pressure regulator. In order that this management was based on something, the control unit obtains data on engine temperature, frequency of rotation, starting processes, the provision of a klapanny lock (from idling to full loading). Here the signal a lambda probe, and also additional data from system of ignition, the sensor of atmospheric pressure and from an automatic transmission is added.
Distributive valve of stabilization of idling
Function: the valve opens the air channel bypassing a butterfly valve. Effect thus the following: because of increased amount of air the flowmeter of air "believes" that the butterfly valve was a little slightly opened, and consequently provides respectively increased intake of fuel. Desirable result: increase in frequency of rotation. How many will in addition arrive air, defines the control unit of system of injection of KE-III-Jetronic, namely according to frequency of rotation at present time. Thereby electronics aspires to return frequency of rotation to a standard range.
Starting fuel valve
It is a nozzle with an electromagnetic drive which depending on engine temperature at start submits additional amount of small sprayed fuel to an inlet collector. Duration of injection defines the control unit of system of injection of KE-III-Jetronic.
Sensor of angular moving of a butterfly valve
In Audi 80 two sensors of angular moving of a butterfly valve are mounted. They signal the following data:
Fuel interruption of supply in a mode of compulsory idling (movement nakaty)
Already mentioned regulator of pressure stops supply of fuel if the car is maintained in a mode of compulsory idling. The control unit distinguishes this mode according to information «frequency of rotation higher, than frequency of rotation in an idling mode» and «is closed a butterfly valve».