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
      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 the 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 electrical system
+ System of ignition
+ Lighting
+ Signaling devices
+ Devices and auxiliary devices
+ Heating and ventilation
+ Body elements
+ Search of malfunctions
+ Specifications





Search of malfunctions

5-cylinder engine: the starting fuel valve (2) with the plug (1).

On an illustration on the right you see the proofreader of composition of gas mixture with the locking valve (1), an air nozzle (2), the air filter (3), the batcher (4), the regulator of pressure (5) and a potentiometer of the locking valve (6).

The drawing shows the correct position of the locking valve with an air nozzle at the left. It has to be exactly on and = 1,9 mm are lower than the upper edge of a narrow cylindrical part of an air nozzle. If necessary to correct by easy bending of the spring (presented in the drawing in the form of "snake"). Attention: flowmeters of air of newer type are supplied with an adjusting bolt instead of a spring. In this case position of the locking valve yustirutsya by the mentioned bolt.


The distributive valve of stabilization of idling of the 5-cylinder engine is located on the right in front at a head of the block of cylinders.


At the removed air inlet sleeve in the case of throttle knot both butterfly valves are visible (3 and 4). Above on the case there is a system of driving drafts (2) which opens at first one, and by further pressing an accelerator pedal the second butterfly valve. The position (1) displays the idling signal switch.

On a head of the block of cylinders in front at the left are in a branch pipe of the cooling system: sensor of temperature of the engine of system of injection (1), and also electronic thermoswitch (2) indicators of temperature of cooling liquid, control bulb of cooling liquid, conditioner, etc.

The chart below shows the size of resistance of the sensor of temperature of cooling liquid depending on temperature.

In the following sections we considered those possibilities of search of malfunctions for which in house conditions no special tools or measuring devices are necessary. If you after reading of our list of malfunctions (at the end of the head) or after reading of memory of the store of malfunctions suspected a certain detail, then here you will find the scheme of control.

Check of vpryskny nozzles

 PERFORMANCE ORDER

  1. To disconnect system of ignition according to the scheme described in the head Sistema of ignition.
  2. To check whether gasoline comes to system of injection, weaken bolts on the bringing fuel-supply line.
  3. Do not forget about a rag because in most cases from a fuel-supply line gasoline will scatter. Otherwise ask the assistant to work as a starter.
  4. If fuel arrives, so supply as it should be – therefore, in the second turn it is necessary to check nozzles.
  5. To remove a nozzle, the description see below in this chapter. For this purpose at first the top part of an inlet collector has to be removed.
  6. To keep in readiness the capacity or a rag for collecting fuel.
  7. To remove a big air duct between the proofreader of composition of gas mixture and the case of throttle knot for receiving access to the locking valve.
  8. To remove in the central distributing device of the relay of the fuel pump on a shtekerny cell 10 (see the head the Fuel tank and the fuel pump).
  9. On a cell 10 to connect shtekerny contacts 48 (or 30) and 52 (or 87) a wire piece. The fuel pump has to start working.
  10. To raise a little a hand the locking valve of the distributor. Now the nozzle has to inject gasoline konusoobrazno. Otherwise:
  11. To lift the locking valve once against the stop. To repeat check.
  12. In the same way it is possible to check a difference in number of injectable fuel between separate cylinders. However this way is good only for want of something better.
  13. To send all five nozzles to five measuring capacities, at the same time not to bend fuel-supply line hoses.
  14. To raise a little (approximately on 2 cm) the locking valve.
  15. The assistant has to support the mentioned crossing point until in the first capacity 20 cm3 (ml) of fuel do not gather.
  16. To compare amount of injectable fuel. The difference should not make more than 2,5 cm3.
  17. In case of big deviations to trade places of a nozzle with the greatest and smallest indicators. To repeat measurement.
  18. If deviations "moved" together with nozzles, so time to replace nozzles with the corresponding deviations came.
  19. If you received former results of measurements on cylinders with deviations, then is not excluded that the fuel-supply line to a nozzle is made narrower or the batcher is faulty.
  20. Check of tightness of nozzles: if to switch-off the fuel pump after two-minute work with the raised locking valve (to remove a crossing point), then fuel from nozzles should not act.

Check of the starting fuel valve

 PERFORMANCE ORDER

  1. To disconnect system of ignition according to the scheme described in the head Sistema of ignition.
  2. To remove the starting fuel valve, to remove a wire tip, to leave connected a fuel-supply line tube.
  3. To work a little as a starter that the fuel pump could create pressure.
  4. To lower a nozzle in capacity, to connect two auxiliary wires to contacts of the valve.
  5. To connect the free ends of wires to accumulator conclusions – one with "+", another with "-".
  6. The valve has to spray gasoline now konusoobrazno.
  7. Check on tightness: to remove auxiliary wires.
  8. To work once again a little as a starter that the fuel pump created pressure.
  9. To absolutely wipe the valve. Within a minute the gasoline postupaniye should not be observed.

Check of the batcher of fuel

 PERFORMANCE ORDER

  1. To work a little as the engine (about 10 c) or a starter that the total pressure of fuel was created.
  2. To uncover also a replaceable element of the air filter.
  3. To remove a big air duct between the proofreader of composition of gas mixture and the case of throttle knot.
  4. Now the locking valve which needs to be extended completely upward is visible. This process has to take place all the time with identical effort.
  5. By bystry pressing of the locking valve resistance should not be felt. Otherwise it is necessary to replace an air flowmeter.
  6. If the locking valve manages to be extended only with great difficulty, but it very easily falls, so in the batcher of fuel the distributive piston froze up. It is necessary to replace the fuel batcher.

Check of a flowmeter of air

 PERFORMANCE ORDER

  1. To warm up the engine up to the working temperature, or to work as the warmed engine during about 10 with before check.
  2. After weakening of collars it is necessary to remove an air inlet sleeve between the proofreader of composition of gas mixture and the case of throttle knot.
  3. To check the locking valve: it has to be from the party turned to the vpryskny pipeline, is 1,9 mm lower than the upper edge of a narrow cylindrical part of an air nozzle, the most bigger is 3 mm deeper.
  4. If the valve is located incorrectly, he can be brought up up and to correct its situation, having bent a fixing wire bracket below in the channel of a flowmeter of air. Not to bend a spring at all!
  5. Check now whether the locking valve of walls concerns.
  6. If this is so, it is necessary to weaken the central fixing screw and to anew align the valve.
  7. After this adjustment it is necessary to recheck idling and maintenance WITH.

Check of stabilization of frequency of idling

 PERFORMANCE ORDER

  1. To include ignition, to touch the distributive valve by a hand: working vibration has to be felt, otherwise either the distributive valve, or the control unit of system of injection KE-III-Jetronic is faulty.
  2. To check the distributive valve: to remove plugs. To measure resistance between shtekerny contacts of the distributive valve: it has to be insignificant. Infinity value means a rupture of a winding – defect of the distributive valve.
  3. If the distributive valve as it should be, then a source of malfunction it is possible to assume in a rupture of conducting or the faulty control unit. To check and, if necessary, to replace.
  4. To connect the LED voltmeter to both poles of a free tip of a wire.
  5. To include ignition.
  6. Volmetr has to flash, in this case giving of power supply from the control unit of system of injection KE-III-Jetronic as it should be.

Check of the sensor of angular movement of a butterfly valve

Models with the mechanical transmission

Contacts of an ohmmeter cannot be connected directly to sensors from which one is located below the case of throttle knot. Therefore separate only plug connection available from above. Measure resistance in conducting of the sensor:

 PERFORMANCE ORDER

  1. Idling signal switch: to connect an ohmmeter to contacts 1 and 2 plugs.
  2. Butterfly valve in the provision of the mode of idling: indicator of 0 Ohms. To slightly slightly open a butterfly valve: the indicator has to pass to Ohm.
  3. Switch of a signal of full loading: to connect an ohmmeter to contacts 2 and 3.
  4. Butterfly valve in the provision of full loading: indicator of 0 Ohms. To slightly cover a butterfly valve: the indicator has to pass to Ohm.

Check of a potentiometer of a butterfly valve

Models with the automatic transmission

 PERFORMANCE ORDER

  1. To separate the triple-pole plug of a potentiometer of a butterfly valve.
  2. For check to connect an ohmmeter to contacts 1 and 2:
  3. The indicator has to make 1,5 – 2,6 kOhm.
  4. Now to connect an ohmmeter to contacts 2 and 3:
  5. The indicator has to make 0,75 – 1,3 kOhm.
  6. To slowly open a butterfly valve, the ohmmeter is connected.
  7. Resistance has to increase a maximum up to 3,6 kOhm.

 Hint: the potentiometer of a butterfly valve can be regulated. However after that it is necessary to carry out "the main adjustment" of the automatic transmission – business for a workshop.

Check of sensors of temperature of the engine

 PERFORMANCE ORDER

  1. The Audi 80 car with system of injection KE-III-Jetronic is supplied with the double temperature sensor for system of injection and completely electronic system of ignition. Measurements at these sensors are made from each of both contacts to "weight" (the block of cylinders).
  2. For check to connect an ohmmeter to one of both contacts and to "weight" (the bared metal of the block of cylinders).
  3. The received indicator of resistance depends on temperature.

Check lambda regulation

Though a functioning inspection a lambda regulation can be carried out rather easily, however the coordinating wire and the ampermeter which is available for many fans of electronics are necessary for it. Or it is possible to carry out an inspection by means of a gas analyzer for determination of content WITH. The description of check is given below:

 PERFORMANCE ORDER

  1. An inspection has to be carried out at the heated-up engine.
  2. To remove pressure regulator plug, to connect the measuring adapter manufactured by you of two suitable plugs and a piece of a wire connecting conducting and the regulator of pressure.
  3. To separate one of the coordinating wires and to bring to the measuring device (milliamperny range).
  4. To start the engine and to leave to work in the idling mode.
  5. To write down the received indicator.
  6. To extend the measuring oil probe.
  7. Current has to increase in a chain of management.
  8. Otherwise one of components a lambda regulation is faulty.
  9. In this case to try to separate shtekerny connection to a lambda probe and to take a green wire to the control unit about 20 with on "weight".
  10. If now current in a chain of management changes, so the control unit of system of injection of KE-III-Jetronc as it should be, but is faulty a lambda probe – to replace.
  11. If nothing occurs, so the control unit of system of injection is faulty.

 Hint: the main prerequisite functioning a lambda regulation is the correct main installation of idling that means that contents WITH meets standard, otherwise regulation will constantly be in one of the ends of standard range. The same conditions are created if mix is strongly impoverished by unaccounted air.








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