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
   - Systems of injection MPI and MPFI
      Operating procedure
      Ljambda-regulation
      Malfunctions and independent diagnostics
      Independent repair
      Visual check
      Check of separate elements
      Removal of elements
      Trosovyj drive of "gas"
      Check of a mode of idling and the analysis of exhaust gases
      The list of malfunctions
+ 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



Check of separate elements

The 2,8-litre engine in a motor compartment behind on the right has the flowmeter of air (marksman) connected by flanges with the case of the air filter.


At the removed tip (1) it is possible to check up food giving to впрыскным to atomizers (2) by means of the light-emitting diode voltmeter. When the engine turn by means of a starter, light-emitting diodes in the voltmeter should замерцать. Otherwise food giving is absent.

Various kinds of execution of the valve of stabilisation of idling. At the left the 2,6-litre engine, on the right – 2,8-litre is represented.

Behind at the left in the engine the gauge of temperature of a cooling liquid (it is screwed in in a hose of system of cooling) for system of ignition/injection (marksman) is located. The diagramme shows size of resistance of the gauge depending on temperature.

Only the 2,6-litre engine is equipped by the gauge of temperature of inlet air (3). It is located behind on the right at the engine near to the valve of stabilisation of idling (1) and a regulator of pressure of giving of fuel (2). The diagramme shows size of resistance of the gauge depending on temperature of inlet air.

Following sections describe check of components of system of injection if that probably to spend house means.

Check впрыскных atomizers

If you had a suspicion that one of atomizers does not work, it is easy for checking up by means of the light-emitting diode voltmeter and an exact ohmmeter.

 PERFORMANCE ORDER

  1. To disconnect tips from all впрыскных atomizers.
  2. At first pressure check: the light-emitting diode voltmeter (not a control lamp) to connect to plug contacts of the tip. To get the engine: light-emitting diodes in the voltmeter should замерцать, otherwise there is no supply of electricity or неиспровен the block of management connecting "weight". With the usual measuring device it is impossible to spend this check.
  3. Resistance check: to separate tips впрыскных atomizers, to connect an ohmmeter to both contacts of an atomizer: on the cold engine it should show 13,5 – 17 Ohm.
  4. If the indicator is behind the specified limits, to replace an atomizer (in the event that gauging was exact).
  5. Tightness check: to remove the fuel distributor together behind atomizers.
  6. Tips впрыскных atomizers are removed, hoses топливопроводов remain connected.
  7. Ask the assistant to turn some times the engine by means of a starter that has earned the fuel pump and working pressure was created.
  8. Observe for впрыскными atomizers: each separately taken atomizer should lose in a minute no more than 1-2 drops of fuel. Otherwise it is necessary to replace not tight atomizer.
  9. Irrespective of it it is possible to check up впрыскную a stream and впрыскное quantity of an atomizer, in a case if it is necessary because of faults in engine work.

Potentiometer throttle заслонки

 PERFORMANCE ORDER

  1. To disconnect the tip of a potentiometer throttle заслонки.
  2. By means of an exact ohmmeter to measure resistance between potentiometer contacts.
  3. It is necessary to measure in positions throttle заслонки "idling" and «full loading» at the idle engine.
  4. The ohmmeter should show following standard indicators:

Position throttle заслонки
To measure between contacts
Standard indicator (clod)
(Not very well)
1 and 2
1,5 – 2,6
Idling
2 and 3
0,75 – 1,3
Full loading
2 and 3
макс. 3,6

Air flowmeter

Only MPI

 PERFORMANCE ORDER

  1. To shift back a rubber tip of a flowmeter of air, the tip to leave connected.
  2. To connect the exact voltmeter from an underside to plug contacts, under the described scheme:
  3. Measurement 1: to connect a connecting wire to contacts 2 and 3. To include ignition.
  4. The voltmeter should show 12 – 14 Century fuel giving Otherwise is faulty.
  5. To check up a safety lock № 27, if necessary to check up a wire from a safety lock № 27 to plug contact 3 flowmeters of air.
  6. Or to check up connection with the engine case (contact 2).
  7. Measurement 2: to Connect a connecting wire to contacts 2 and 4.
  8. To include ignition.
  9. The voltmeter should show 1,0 – 7,5 Century Otherwise are available defect With-potentiometer in air flowmeter. To replace air flowmeter.
  10. Measurement 3: to Connect a connecting wire to contacts 1 and 2.
  11. To include ignition.
  12. The voltmeter should show 0,3 – 1,1 Century
  13. To start the engine (the wire remains connected). To switch off all consumers of an electricity, to track, that the fan of system of cooling did not work.
  14. Constantly to change frequency of rotation of a shaft of the engine between idling and 4000 rpm.
  15. The voltmeter should show (depending on frequency of rotation) between 1,5 and 3,4 Century Otherwise are maximum air flowmeter is faulty. To replace.

The valve of stabilisation of frequency of idling

Only MPI

The valve of stabilisation of frequency of rotation at the 2,8-litre engine is located on the right on the case of throttle knot. It is checked as follows:

 PERFORMANCE ORDER

  1. To disconnect the tip of the valve of stabilisation of idling and to connect to both plug contacts of the valve an exact ohmmeter.
  2. The device should show 7—11 Ohm, otherwise the valve is faulty.
  3. The further check of action: to remove the valve of stabilisation of idling; the tip remains connected. Rotating piston in an aperture for air passage to the valve to result in position is opened"or"is closed"(thus not to apply metal tools!).
  4. To include ignition and to observe of the rotating piston: it should rise approximately in average position.
  5. To check up ease of a course of the rotating piston: it can be actuated abrupt проворачиванием the taken out valve.
  6. Besides, on the piston there should not be traces of a friction or grooves.

The valve of stabilisation of frequency of idling

Only MPFI

 Attention! The valve of stabilisation of idling of the 2,6-litre engine cannot be dismantled make-shifts because after repeated installation becomes system of injection necessary so-called basic adjustment, and it can be made only by means of the device of reading of memory of the store V. A. G. 1551 in workshop Audi.

If the tip of the valve of stabilisation of idling to disconnect before the expiration of one and a half hours after last cessation of work of the engine in memory of the store of malfunctions malfunction «registers the valve of stabilisation of idling» (that, maybe, at all does not correspond to true) is faulty.

To check up on this valve it is possible only a winding:

 PERFORMANCE ORDER

  1. To separate the tip of the valve of stabilisation of idling.
  2. To measure resistance between plug contacts of the valve 1 and 4, and also 2 and 3 by means of an exact ohmmeter.
  3. If the valve is serviceable, resistance should make accordingly 45—60 Ohm, otherwise the valve it is necessary to consider faulty.
  4. The further checks by house means cannot be spent.
  5. If the workshop replaces the valve simultaneously she spends and the mentioned basic adjustment.

The gauge of temperature of a cooling liquid for ignition/injection system

 Attention! If the tip of the gauge of temperature of a cooling liquid of model with the 2,6-litre engine to disconnect before the expiration of one and a half hours after engine cessation of work in memory of the store of malfunctions registers: «the gauge of temperature of a cooling liquid is faulty» (that, maybe, at all does not correspond to true).


The temperature gauge can cause that in certain temperature ranges in engine work malfunctions are shown. Check:


 PERFORMANCE ORDER

  1. To disconnect the tip of the gauge of temperature of a cooling liquid.
  2. By means of an exact ohmmeter to measure resistance between both plug contacts of the gauge.
  3. To compare the received result of check to standard indicators under the diagramme above depending on temperature of cooling means. If the indicator strongly deviates from standard, to replace the temperature gauge.
  4. As addition two more average indexes of resistance: at 20°С resistance should make temperatures of a cooling liquid about 2,5 clod, at 80°С – about 330 Ohm.

The gauge of temperature of inlet air

Only MPFI

 Attention! If the tip of the gauge of temperature of inlet air to disconnect before the expiration of one and a half hours after engine cessation of work in memory of the store registers: «the gauge of temperature of inlet air is faulty» (that, maybe, at all does not correspond to true).


 PERFORMANCE ORDER

  1. To disconnect the tip of the gauge of temperature of inlet air.
  2. By means of an exact ohmmeter to measure resistance between both plug contacts of the gauge.
  3. To compare the received result of check to standard indicators under the diagramme above depending on temperature of inlet air. If the indicator strongly deviates from standard, to replace the temperature gauge.
  4. As addition one more average index of resistance: at 20°С (a room temperature, the cold engine) resistance should make about 6,3 clod.

Ljambda-probe check

For this check it is necessary to separate plug connection in conducting to a ljambda-probe. Where there are plug connections to the left and right probe.

Shtekernye connections behind in a motor compartment:

1 – ljambda-probe heating (the right probe);
2 – to the ignition coil (bringing conducting);
3 – for a ljambda-probe signal (the right probe; штекерное connection is behind at the holder);
4 – for the gauge of detonation ignition I;
5 – for the gauge of frequency of rotation of a shaft of the engine; 6 – for the gauge of the moment of ignition.

Shtekernye connections behind at the left in a motor compartment:

1 – for a ljamda-probe (the left ljambda-probe);
2 – ljambda-probe heating (the left probe);
3 – the gauge of detonation combustion II.


 PERFORMANCE ORDER

  1. Check is made by means of an exact ohmmeter:
  2. Check of special heating: to separate the tip to heating of a ljambda-probe.
    To connect an ohmmeter to both contacts of a cable of heating of a probe.
  3. Standard indicator at serviceable heating 3—15 Ohm.
  4. Otherwise to replace a ljambda-probe.
  5. Ljambda-probe check: to separate the tip to a ljambda-probe (the calibrated wire).
  6. To connect an ohmmeter to tip contacts, to a probe and to the engine case.
  7. Standard indicator at a serviceable probe: the Ohm.
  8. Otherwise to replace a ljambda-probe.
  9. Line check to the management block: to disconnect the tip from a ljamda-probe (the calibrated wire) (as already did).
  10. To connect the voltmeter to tip contacts to the block of management and to the engine case.
  11. At serviceable conducting the indicator should make 0,35—0,45 Century
  12. Otherwise to check up conducting.
  13. If conducting is perfectly in order, to replace the management block.

Ljambda-probe replacement

 PERFORMANCE ORDER

  1. To disconnect tips of wires, to weaken bandages of cables.
  2. Before probe installation to grease a carving with assembly paste. On a cut of a probe paste should not to get. The inhaling moment: 50 Н•м.