Audi 80/Avant (B4)

Since 1991-1995 of release

Repair and car operation



Audi 80/Avant
+ The description
+ Engines
+ System of release of the fulfilled gases
+ Cooling system
+ Fuel tank and the fuel pump
+ The air filter and воздухозаборные channels
- Injection system
   + System of injection Mono-Motronic
   + System of injection Digifant
   - System of injection KE-III-Jetronic
      Basic elements
      Operating procedure
      Ljambda-regulation
      Malfunctions and independent diagnostics
      Independent repair
      Visual check
      Check of separate elements
      Search of malfunctions
      Removal of components
      Check of a mode of idling and the analysis of exhaust gases
      The list of malfunctions
   + Systems of injection MPI and MPFI
+ Coupling
+ Transmission and transmission
+ Suspension bracket and steering
+ Brake system
+ Antiblocking system of brakes
+ Wheels and tyres
+ Kuzovnaja electrosystem
+ Ignition system
+ Illumination
+ Signalling devices
+ Devices and auxiliary devices
+ Heating and ventilation
+ Body elements
+ Search of malfunctions
+ Specifications



Operating procedure

Interaction of components

Start: the depression created by soaking up pistons of the engine, lifts запорный the valve in air flowmeter. Thanks to it the distributive piston supposes fuel inflow to впрыскным to atomizers. In an operating time of a starter the starting fuel valve submits to admission system additional quantity of fuel – if the engine still cold. Only in this case the management block supposes similar injection. The maximum duration of injection also depends on temperature.

Phase of warming up of the engine: that the engine worked in regular intervals first minutes after start-up, the distributive valve of stabilisation of idling opens the channel on which inlet air can arrive bypassing throttle заслонки.

In addition the pressure regulator lets in more fuel through atomizers. The increase in receipt of air and fuel allows to reach the raised frequency of rotation in a phase of warming up of the engine at the enriched mix.

With engine rise in temperature the distributive valve blocks air access more and more. In parallel with this process the quantity of arriving fuel is normalised, the pressure regulator reduces quantity of injected fuel.

Idling: for achievement of uniform frequency of rotation of a shaft of the engine in a mode of idling and soft приемистости in the bottom range of frequencies of rotation round everyone впрыскной atomizers in the combustion chamber air arrives. It leads to smaller dispersion of fuel. Air aspires to впрыскным to atomizers through the connecting union in a head of the block of cylinders and the special air channel. The distributive valve for stabilisation of frequency of rotation allows to arrive большему to quantity of inlet air bypassing throttle заслонки if frequency of rotation falls below standard size.

Normal operation and acceleration of the car do not demand any special adaptations. The klapannyj shutter in air flowmeter rises or falls depending on the arrived quantity of air. Fuel receipt to впрыскным to atomizers accordingly varies: a lot of air – is a lot of fuel, it is not enough air – not enough fuel. Thus, the parity is absolutely automatically established always correct combustion most favourable to process.

Full loading: the gauge of angular moving throttle заслонки at completely squeezed out pedal of an accelerator signals the management block that now from the engine the maximum capacity is required. Thereby the pressure regulator receives a command a tax to впрыскным to atomizers of a bit more fuel, than usually.

Fuel stopping delivery in a mode of compulsory idling (movement накатом): function of a stopping delivery of fuel in a mode of compulsory idling disconnects fuel giving if the car goes downhill and thus the accelerator pedal is not squeezed out.