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
      Basic elements
      Operating procedure
      Lambda 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 analysis of exhaust gases
      List of malfunctions
   + Systems of injection of MPI and MPFI
+ 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


scat slave



Lambda regulation

Plug connections to a lambda probe:

1–heating lambda probe;
2–signal lambda probe.

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, the system of injection of KE-III-Jetronic is supplied so-called a lambda regulation.

Thus the lambda probe measures amount of oxygen in the fulfilled gases – comparative size for structure of a mix of fuel/air. If the indicator deviates from ideal, the control unit gives an assignment to a pressure regulator in the proof-reader of composition of gas mixture immediately to change mix structure. Regulation works (any колебательно because only in this case catalytic converter copes with almost complete transformation of harmful substances) in a range from l = 0,8 to l = 1,2.

The lambda probe transmits a signal only after the temperatures exceeding 350°С therefore it electricly is warmed (in addition to temperature of the fulfilled gases). Until then while it will not reach the working temperature, the system is lagged behind noncontrollable and is guided by the set average factor. In the same way regulation occurs, if enrichment of gas mixture in the conditions of full loading is activated.