Audi 80/Avant (B4)

since 1991-1995 of release

Repair and car operation


Audi 80/Avant
+ Technical specification
+ Engines
+ 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
   - Systems of injection of MPI and MPFI
      Operating procedure
      Lambda regulation
      Malfunctions and independent diagnostics
      Independent repair
      Visual check
      Check of separate elements
      Removal of elements
      Hummock drive of "gas"
      Check of a mode of idling and analysis of exhaust gases
      List of malfunctions
+ Coupling
+ Transmission and transmission
+ Suspension bracket and steering
+ Brake system
+ Anti-blocking system of brakes
+ Wheels and tires
+ Body electrosystem
+ ignition System
+ Lighting
+ Signalling devices
+ Devices and auxiliary devices
+ Heating and ventilation
+ body Elements
+ Search of malfunctions
+ Specifications



Lambda regulation

Catalytic converter can correctly work only if the factor of excess of air l is probably closer to 1 that corresponds to a fuel/air 14,7:1 ratio. In order that it was carried out in practice, systems of injection of MPI/MPFI are supplied so-called a lambda regulation. Thus the lambda probe measures amount of oxygen in exhaust gases – comparable size for structure of a mix of fuel/air. If the indicator deviates from ideal, the control unit regulates mix structure.

Regulation works in a range from l = 0,8 to l = 1,2, and fluctuations of this value are welcomed, because only in this case catalytic converter copes with almost complete transformation of harmful substances.

The lambda probe transmits a signal only after the temperatures exceeding 350°С. In order that this temperature range was reached as soon as possible, the probe is warmed electricly. Until then while the probe will not reach the working temperature, the system is lagged behind noncontrollable and is guided on the set average factor.

As you already guessed: 6-cylinder Audi is supplied with two catalytic converters and also two lambda probes.