Audi 80/Avant (B4)

since 1991-1995 release

Repair and operation of the car



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
- System of injection
   + System of injection Mono-Motronic
   + System of injection Digifant
   + System of injection 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 the 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 electrical system
+ System of ignition
+ Lighting
+ Signaling 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 a flowmeter of air (shooter) connected by flanges to the case of the air filter.


At the removed plug (1) it is possible to check giving of food to vpryskny nozzles (2) by means of the LED voltmeter. When the engine is turned by means of a starter, light-emitting diodes in the voltmeter have to flicker. Otherwise giving of 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 cooling system hose) for system of ignition/injection (shooter) is located. The chart shows sensor resistance size 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 the regulator of pressure of supply of fuel (2). The chart shows sensor resistance size depending on temperature of inlet air.

The following sections describe check of components of system of injection if it is possible to carry out that by house means.

Check of vpryskny nozzles

If you had a suspicion that one of nozzles does not work, it is easy to check it by means of the LED voltmeter and an exact ohmmeter.

 PERFORMANCE ORDER

  1. To disconnect plugs from all vpryskny nozzles.
  2. At first check of tension: to connect the LED voltmeter (not a control lamp) to plug contacts of the plug. To start the engine: light-emitting diodes in the voltmeter have to flicker, otherwise there is no supply of electricity or the control unit connecting "weight" is faulty. With the ordinary measuring device this inspection cannot be carried out.
  3. Check of resistance: to separate plugs of vpryskny nozzles, to connect an ohmmeter to both contacts of a nozzle: on the cold engine it has to show 13,5 – 17 Ohms.
  4. If the indicator is beyond the specified limits, to replace a nozzle (in case the measurement was exact).
  5. Tightness check: to remove the fuel distributor together behind nozzles.
  6. Plugs of vpryskny nozzles are removed, hoses of fuel-supply lines 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 has to lose no more than 1 — 2 thaw of fuel a minute. Otherwise it is necessary to replace an untight 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.

Potentiometer of a butterfly valve

 PERFORMANCE ORDER

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

Provision of a butterfly valve
To measure between contacts
Standard indicator (kOhm)
(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, to leave the plug 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 has to show 12 – 14 Century. Otherwise fuel supply 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 has to show 1,0 – 7,5 Century. Otherwise defect WITH - a potentiometer in an air flowmeter is available. 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 has to show 0,3 – 1,1 Century.
  13. To start the engine (the wire remains connected). To switch off everything consumers of electricity, to track that the cooling system fan did not work.
  14. It is constant to change the frequency of rotation of a shaft of the engine between idling and 4000 rpm.
  15. The voltmeter has to show (depending on rotation frequency) 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 plug of the valve of stabilization of idling and to connect an exact ohmmeter to both plug contacts of the valve.
  2. The device has to show 7 — 11 Ohms, otherwise the valve is faulty.
  3. Further check of action: to remove the idling stabilization valve; the plug remains connected. To bring the rotating piston in an opening for passing of air in the valve into situation "is open" or "closed" (at the same time not to use metal tools!).
  4. To include ignition and to watch the rotating piston: he has to get up approximately in average situation.
  5. To check ease of the course of the rotating piston: it can be set in motion an abrupt provorachivaniye of the taken-out valve.
  6. Besides, on the piston there should not be traces of 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 there is necessary a so-called main adjustment of system of injection, 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 the workshop Audi.

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

It is possible to check on this valve only a winding:

 PERFORMANCE ORDER

  1. To separate the idling stabilization valve plug.
  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 has to make respectively 45 — 60 Ohms, otherwise the valve should be considered faulty.
  4. Further checks by house means cannot be carried out.
  5. If the workshop replaces the valve, then at the same time she carries out also the mentioned main adjustment.

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

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


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


 PERFORMANCE ORDER

  1. To disconnect the plug 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 the cooling means. If the indicator strongly deviates standard, to replace temperature sensor.
  4. As addition two more average values of resistance: at 20 °C of temperature of cooling liquid resistance has to make about 2,5 kOhm, at 80 °C – about 330 Ohms.

Sensor of temperature of inlet air

Only MPFI

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


 PERFORMANCE ORDER

  1. To disconnect the plug 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 standard, to replace temperature sensor.
  4. As addition one more average value of resistance: at 20 °C (room temperature, the cold engine) resistance has to make about 6,3 kOhm.

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.

Shtekerny connections behind in a motor compartment:

1 – heating lambda probe (right probe);
2 – to the ignition coil (the 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 ignition moment sensor.

Shtekerny connections behind at the left in a motor compartment:

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


 PERFORMANCE ORDER

  1. Check is made by means of an exact ohmmeter:
  2. Check of special heating: to separate the plug to heating a lambda probe.
    To connect an ohmmeter to both contacts of a cable of heating of the probe.
  3. Standard indicator at correct heating of 3 — 15 Ohms.
  4. Otherwise to replace a lambda probe.
  5. Check lambda probe: to separate the plug to a lambda probe (the calibrated wire).
  6. To connect an ohmmeter to contacts of the plug, to the probe and to the engine case.
  7. Standard indicator at the serviceable probe: Ohm.
  8. Otherwise to replace a lambda probe.
  9. Check of the line to the control unit: to disconnect the plug from the lyamda-probe (the calibrated wire) (as already did).
  10. To connect the voltmeter to contacts of the plug to the control unit and to the engine case.
  11. At correct conducting the indicator has to 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 the probe to grease a carving with assembly paste. On a probe cut paste should not get. Inhaling moment: 50 N • m.







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