Audi A3

since 1997 of release

Repair and car operation

Audi A3
+ Maintenance instruction
+ Current leaving and service
+ Engine
+ Systems of cooling, heating
- Power supply system and production of the fulfilled gases
   + Power supply system
   - System of injection of fuel
      General information and security measures
      Removal, installation and check of the fuel distributive highway and injectors
      Check and adjustment of number of turns of the single course/the moment of ignition/concentration WITH
   + System of injection of the diesel engine
   + System of production of the fulfilled gases
+ engine Electric equipment
+ Manual box of gear shifting
+ Automatic transmission and models with a full drive
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment
+ Elektroskhema


Removal, installation and check of the fuel distributive highway and injectors


The fuel distributive highway with injectors

1-lock bracket
Watch the correct situation on an injector and the highway.
3-regulator of pressure of fuel
4-sealing ring
At damage replace
6-fuel distributive highway
7-accession of return of fuel
8-accession of supply of fuel


1. Disconnect a vacuum hose and расстыкуйте the socket of the valve of switching at the inlet pipeline. Remove tips of spark plugs.
2. Unscrew screws with an internal shestigrannik (are specified by shooters) and reject the top part of the inlet pipeline.


On an illustration the engine of 1.8 l is shown.

3. Disconnect a vacuum hose from a regulator of pressure of fuel.


The fuel system is under pressure! When opening system fuel can escape, bring together him a rag. Use thus goggles. Do not smoke, do not use open fire, danger of emergence of a fire! Keep in readiness the fire extinguisher.

4. Disconnect from the fuel distributive highway the pressure head pipeline, thus collect following fuel a rag.
5. Rasstykuyte I will corrode to injectors.
6. Turn out bolts of fastening of the fuel distributive highway and take out from a final collector in a set injectors with the fuel distributive highway.


On an illustration the engine of 150 h.p. is shown.

7. Remove clips of connection of injectors and the fuel distributive highway. Take out injectors from the fuel distributive highway. Injectors only are inserted, but not fixed.


Do not interchange the position of injectors, establish them in a former place.



At installation of injectors into place watch to damaging sealing rings and injectors in a head of cylinders. Sealing rings surely replace with the new. Thus it is not necessary to remove forward plastic plugs from injectors.

8. Slightly grease sealing rings before installation into place pure impellent oil.
9. Insert injectors vertically against the stop into the fuel distributive highway and fix brackets.
10. Carefully insert the highway with injectors into the inlet pipeline and press against the stop.
11. Establish fastening bolts, slightly press hands the fuel distributive highway in the direction of the inlet pipeline and tighten bolts the moment of 10 N of m.
12. Join shtekerny connections of injectors.
13. Fix submitting pipeline at the fuel distributive highway.
14. Connect the vacuum pipeline at a pressure regulator.
15. Fix the top part of the inlet pipeline with new laying.
16. Connect a vacuum hose and the connecting tip of the valve of switching at the inlet pipeline.
17. Join shtekerny connections of spark plugs.
Check of injectors

Fuel injectors are the electromagnetic valves opened and closed by a control unit of the engine which defines time of opening and duration of injection of fuel, depending on turns of a cranked shaft of the engine, the provision of a butterfly valve, size of the arriving weight of air, temperature of air arriving in the engine, temperature of cooling liquid and availability of oxygen in exhaust gases on the basis of information, received from the sensors established on the engine and round it. Injectors spray fuel a cone-shaped stream. After fuel dispersion the valve of an injector is closed not tightly, problems are possible at start of the hot engine. At faulty injectors the engine can continue to work and after ignition switching off, in a mode of kalilny ignition.
18. Before check of injectors check a condition and operability of a safety lock of a control system of the engine, the sensor of turns of a cranked shaft and the relay of the fuel pump.
Check of giving of tension to injectors
19. Disconnect the electric socket from an injector of the first cylinder.
20. Connect to socket contacts a control light-emitting diode. At a provorachivaniye of a cranked shaft of the engine a starter the light-emitting diode should blink.
21. Similarly check tension giving to other fuel injectors.
The light-emitting diode does not blink on one of cylinders
22. Connect a control light-emitting diode to contact of No. of 1 electric socket for tension giving to an injector and mass of the car. Connect contact No. 2 of the electric socket to mass of the car.
23. Turn a cranked shaft of the engine a starter. Thus the light-emitting diode should blink. Otherwise check all electric power-supply circuit of injectors.
The light-emitting diode does not blink only on one or on several cylinders
24. Check a condition of an electric power-supply circuit of injectors, define and eliminate a place of break of an electric chain or its short circuit on weight. Also check operation of the control unit as the engine.
Resistance check
25. Consistently disconnect electric sockets from injectors and, using an ohmmeter, check resistance of injectors which should be in limits from 12 to 17 Ohm.


On the engine, heated-up to normal working temperature, resistance of injectors increases by 4-6 Ohm.

26. If resistance of an injector differs from demanded, replace it.
Check of a stream of dispersion and tightness of the valve of an injector
27. Disconnect the four-contact electric socket from the sensor of temperature of cooling liquid.
28. Close contacts 1 and 3 sensors resistance of 15 Ohm.
29. Remove the fuel highway together with injectors, without disconnecting from it fuel hoses.
30. Insert injectors into measuring vessels, for example VAG 1602.
31. Ask the assistant to include a starter for some seconds. At starter work injectors should spray fuel. Check a stream of dispersion of fuel which should have a cone-shaped form and to be identical at all injectors.
32. Switch off ignition and check tightness of injectors. Within 1 minute from injectors no more than two drops of fuel should flow out.
33. Establish the fuel highway together with injectors on the engine. Before installation check a condition and grease sealing rings of injectors.
34. Connect the electric socket to the sensor of temperature of cooling liquid.
35. Connect the multicontact electric socket to the control unit the ignition coil.
36. Establish the top casing of the engine.
Check of a regulator of pressure
37. For exact measurement of pressure of fuel the special manometer of VAG1318 with additional details which allows to measure control sizes is used. Pressure idling makes 2.5 bar. At removal of a vacuum hose in a place shown by an arrow, pressure increases to 3.0 bar. After the engine will stop, pressure should be not less than 2.3 bar. At the same time pressure through 10 mines should fall to 2.0 bar.
Check of the sensor of temperature of cooling liquid
38. The sensor carries out a double task. First, he reports temperature of cooling liquid in the engine and, secondly, it incorporates to the remote thermometer on the dashboard. The sensor 2 is on the back party of a head of cylinders. If it is established the conditioner, the second sensor of temperature–1–is in close proximity. For check do the following:
39. Remove the sensor tip.
40. Connect an ohmmeter to two contacts of the tip 1 and 3. On the cold engine and at room temperature of the indication of an ohmmeter should be between 1.5 and 3.0 kiloohms. If it not so establish the new sensor.
Check of the sensor of temperature of soaked-up air
The sensor is established only on engines with a turbokompressor. The sensor is established near the control unit a butterfly valve.
41. Remove the sensor tip.
42. Connect an ohmmeter to sensor contacts. On the cold engine and at room temperature resistance should make 1.6 – 2.8 kiloohms. Otherwise replace the sensor.
Check of a measuring instrument of weight of soaked-up air
If there is no sufficient experience in electric measurements, can be checked only tension giving to a measuring instrument and connection with the control unit. Measuring instruments of weight of air on the engine with a turbokompressor and without it – differ. On the engine without a turbokompressor it is built in the case of the air filter. The light-emitting diode sampler is necessary for check.
43. Disconnect the tip from a measuring instrument of weight of air.

44. Connect щупы a light-emitting diode sampler between contact 3 tips and "weight".
45. The assistant should include a starter (to get the engine). If the light-emitting diode lights up, tension on a measuring instrument moves.
46. To check control unit connections, switch off ignition and remove the tip from the block. Now it is necessary to check current passing.
47. On the engine tip without a turbokompressor, connect an ohmmeter between a conclusion 1 on the tip of the control unit and contact 2 tips of a measuring instrument of weight of air. Besides measure resistance between contact 9 and contact 2. In both cases there should be a conductivity (0 Ohm).