Audi 100/A6

1990-1997 of release

Repair and car operation



Audi 100/A6
+ 1. Maintenance instruction
+ 2. Maintenance
+ 3. Engines
+ 3.2. Diesel engines
+ 3.3. Removal and partition of engines
+ 4. Cooling system
+ 5. Heating and ventilation
- 6. Fuel system
   + 6.1.2. Technical characteristics
   + 6.2. Multipoint system of injection of fuel
   - 6.3. System of injection of MPI/MPFI (6-cylinder engines)
      6.3.2. Technical characteristics
      6.3.3. Distinctions of systems of injection
      6.3.4. Sensors
      6.3.5. Idling regulation
      6.3.6. Removal and installation of klapanny nozzles
      6.3.7. Check of klapanny nozzles
      6.3.8. Oxygen sensor
   + 6.4. Power supply system of diesel engines
   6.5. Device of service of heating
   6.6. Diagnostics of malfunctions of system of heating
   6.7. Conditioner: not only "pluses", but also "minuses"
   6.8. Rules of service of the conditioner
+ 7. Exhaust system
+ 8. Systems of start, ignition
+ 9. Transmission
+ 10. Brake system
+ 11. Suspension brackets, steering
+ 12. Body
+ 13. Electric equipment
+ 14. Good advice


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6.3.4. Sensors

GENERAL INFORMATION

The sensor of temperature of cooling liquid will screw in the pipeline on which cooling liquid from both heads of cylinders circulates. Thus it is a question of the resistance thermometer (NTC resistance) in which resistance changes according to engine temperature. Information on temperature of cooling liquid serves as a correcting factor for an advancing of ignition and duration of injection at the cold and hot engine. Other functions, such as management of a detonation and a retsirkulyatsiya of the fulfilled gases, join at the corresponding temperature of the engine.

The sensor of an advancing of ignition is inductive, it is established on the left side of an engine case. The signal of the sensor of an advancing of ignition is necessary at engine start-up, that together with a signal of the sensor of the Hall to define VMT in the third cylinder of the engine at the moment of ignition. In the absence of a signal the engine is not started.

The sensor of the Hall is at a back end face of the left head of cylinders. The principle of operation of the sensor is stated at the description of distributive system of ignition. The signal of the sensor is necessary at engine start-up, that together with a signal of the sensor of an advancing of ignition to define VMT in the third cylinder of the engine at the moment of ignition. In the absence of a signal the engine is not started.

The sensor of frequency of rotation of a cranked shaft will tighten at a gear wreath of a flywheel. Its signal allows the control unit to calculate an advancing of ignition and the moment of the beginning of injection. In the absence of a signal the engine is not started.

The switch of idling and potentiometer of a butterfly valve are located in the general case at butterfly valve knot. They define the provision of a butterfly valve for the control unit. Thanks to it the dvizhkovy switch as until contact of the switch of idling is not included, in particular, copes and at the same time frequency of rotation of a cranked shaft exceeds a certain value, the control unit blocks supply of fuel to the engine.

Both sensors of detonation combustion are located from the interior of blocks of cylinders in the top part of average cylinders a little below heads of cylinders. Selective regulation of a detonation provides maintenance of an advancing of ignition on border of a detonation and automatically adapts to quality of used fuel. Regulation of a detonation allows to have to the engine high extent of compression. Thanks to it energy of fuel is better used that at the same time conducts to decrease in its expense. The system of regulation turns on sensors of detonation combustion and the corresponding analyzing electronics. Owing to high extent of compression of the engine there can come detonation combustion which at a certain duration causes engine damage. That it to avoid, sensors of detonation combustion which register violations of combustion are required and care of changing an ignition advancing on more later. At failure of the sensor of detonation combustion the control unit automatically rearranges an advancing on more later so that the engine did not receive damages. First of all, it is connected with reduction of capacity which also comes when instead of unleaded Super gasoline (or AI 98) in a fuel tank is filled in with AI 95 ordinary unleaded gasoline (AI 91).

Both oxygen sensors are screwed in the corresponding final branch pipes. They measure in cars with the adjustable catalyst the content of oxygen in the fulfilled gases and send the corresponding signal of tension to the control unit. According to it the control unit changes qualitative structure of a soaked-up fuel and air mix so that in the catalyst the fulfilled gases optimum burn down.