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




Check of separate elements

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


At the removed tip (1) it is possible to check food giving to vpryskny nozzles (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 giving of a food is absent.

Different types of execution of the valve of stabilization of idling. At the left the 2,6-liter engine, on the right – 2,8-liter is represented.

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

Only the 2,6-liter engine is equipped with the sensor of temperature of inlet air (3). It is located behind on the right at the engine near the valve of stabilization of idling (1) and a regulator of pressure of supply of fuel (2). The chart shows size of resistance of the sensor depending on temperature of inlet air.

The following sections describe check of components of system of injection if that is possible for carrying out house means.

Check of vpryskny nozzles

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

 PERFORMANCE ORDER

  1. To disconnect tips from all vpryskny nozzles.
  2. At first tension 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 the control unit connecting "weight" is faulty. With the ordinary measuring device it is impossible to carry out this check.
  3. Resistance check: to separate tips of vpryskny nozzles, to connect an ohmmeter to both contacts of a nozzle: on the cold engine it should show 13,5-17 Ohm.
  4. If the indicator is beyond the specified limits, to replace a nozzle (in case measurement was exact).
  5. Tightness check: to remove the fuel distributor together behind nozzles.
  6. Tips of vpryskny nozzles are removed, hoses топливопроводов remain connected.
  7. Ask the assistant to turn several times the engine by means of a starter in order that earned the fuel pump and working pressure was created.
  8. Watch vpryskny nozzles: each separately taken nozzle should lose no more than 1 — 2 thaws of fuel in a minute. Otherwise it is necessary to replace not tight nozzle.
  9. Irrespective of it it is possible to check a vpryskny stream and vpryskny quantity of a nozzle in case it is necessary because of interruptions in operation of the engine.

Butterfly valve potentiometer

 PERFORMANCE ORDER

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

Provision of a butterfly valve
To measure between contacts
Standard indicator (kiloohm)
(No matter)
1 and 2
1,5-2,6
Idling
2 and 3
0,75-1,3
Full loading
2 and 3
Max. 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 a reverse side to plug contacts, according to 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. Otherwise supply of fuel is faulty.
  5. To check a safety lock No. 27, if necessary to check a wire from a safety lock No. 27 to plug contact 3 flowmeters of air.
  6. Or to check 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 it is available defect WITH - a potentiometer in an air flowmeter. To replace an 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 everything 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 at most 3,4 Century. Otherwise the air flowmeter is faulty. To replace.

Valve of stabilization of frequency of idling

Only MPI

The valve of stabilization of frequency of rotation at the 2,8-liter 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 stabilization 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. Further check of action: to remove the valve of stabilization of idling; the tip remains connected. The rotating piston in an opening for air passing in the valve to bring into situation "is open" or closed" (thus not to apply metal tools!).
  4. To include ignition and to watch the rotating piston: it should rise approximately in average situation.
  5. To check ease of a course of the rotating piston: it can be actuated an abrupt provorachivaniye of the taken-out valve.
  6. Besides, on the piston there should not be traces of a friction or grooves.

Valve of stabilization of frequency of idling

Only MPFI

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

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

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

 PERFORMANCE ORDER

  1. To separate the tip of the valve of stabilization 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 respectively 45 — 60 Ohm, otherwise the valve it is necessary to consider faulty.
  4. Further checks by house means cannot be carried out.
  5. If the workshop replaces the valve, at the same time she will see off and the mentioned main adjustment.

The sensor of temperature of cooling liquid for ignition/injection system

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


The sensor of temperature can cause that in certain temperature ranges in operation of the engine malfunctions are shown. Check:


 PERFORMANCE ORDER

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

Sensor of temperature of inlet air

Only MPFI

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


 PERFORMANCE ORDER

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

Check lambda probe

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

Shtekernye of connection behind in a motor compartment:

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

Shtekernye of connection behind at the left in a motor compartment:

1–for a lyamda-probe (left a lambda probe);
2–heating lambda probe (the left probe);
3–sensor of detonation combustion of II.


 PERFORMANCE ORDER

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

Replacement lambda probe

 PERFORMANCE ORDER

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