Audi A4

since 1994 release

Repair and operation of the car


A4 Audi
+ Running gear
+ Regular servicing
+ Engines
+ Turbo-supercharging
+ System of an exhaust
+ Cooling system
+ Fuel tank and fuel pump
+ Air filter and channels of absorption
- System of injection
   - System of injection of Motronic
      The major knots
      So the system of injection of Motronic functions
      Violations in work and self-diagnostics
      The self-help at injection
      Visual control
      Search of malfunctions in separate knots
      Check of idling and exhaust gases
      Check of exhaust gases (AU)
      Cable of a butterfly valve
      The help at malfunctions
   + System of injection of MPI and MPFI
+ Coupling
+ Transmission and main transfer
+ Suspension bracket of wheels and steering
+ Brakes
+ Wheels and tires
+ Electrotechnical equipment
+ System of ignition
+ Lighting
+ Alarm equipment
+ Tools and devices
+ Heating and ventilation
+ body Details
+ Salon
Search of malfunctions
Technical characteristics



Search of malfunctions in separate knots

Pressure regulator

Measurement of pressure requires the corresponding manometer (V.A.G 1318) with the locking crane and the adapter.

Nominal size idling about 3,5 bars; in the vacuum hose removed from the regulator of pressure, about 4 bars.

Minimum supported pressure directly after switching off of the engine of at least 3 bars; in 10 min. about 2,5 bars.

Check of valves of injection

Here the socket (1) valve of injection is disconnected (2). Tension indicator with a light-emitting diode carries out check of giving of tension on injection valves.


 PERFORMANCE ORDER

  1. Check of giving of tension: dismantle facing of a compartment of the engine with a working volume of 1,6 l (head Dvigateli); at the engine with a working volume of 1,8 l pull for back edge a cover over injection valves up in the beginning, then take out it from the forward party.
  2. Disconnect sockets of valves of injection. For this purpose wring out wire clamps on their reverse side.
  3. Connect to contacts of the disconnected socket tension indicator with a light-emitting diode.
  4. Let your assistant will turn the engine a starter.
  5. The light-emitting diode of the indicator of tension has to flash, otherwise defect in the wire brought to injection valves or in the Motronic control unit.
  6. Check of valves of injection: disconnect all sockets of valves of injection.
  7. Connect an ohmmeter to both contacts of the first valve of injection.
  8. Nominal size: 14–16 W (engine of 1,6 l) and 11–13 W (engine of 1,8 l).
  9. Deeper check (type of a stream and tightness):
  10. Dismantle injection valves together with a distributive tube – see in the head above. But sockets of wires remain connected, and fuel pipes screwed.
  11. Close the resembling opening traffic jams in injection valves.
  12. Lower injection valves in four measured glasses.
  13. Let your assistant within several seconds turn the engine a starter: a stream of injection have to be identical at all valves. Then picture of a type of a stream as it should be.
  14. Disconnect all sockets of valves of injection.
  15. Switch off ignition and then include it approximately on 5 with: from each valve no more than 2 drops have to act. In this case valves are tight.

At the turbo engine the sensor of temperature of the soaked-up air (2) is placed on an inlet collector behind knot of management of a butterfly valve (1).

At the left: this engine with a working volume of 1,8 l with climatic installation has two sensors of temperature on a flange behind a head of the block of cylinders. The figure "1" designated the sensor of climatic installation. In figure "2" – the sensor of system of ignition/injection and the indicator of temperature.

At the engine with a working volume of 1,6 l the sensor of temperature is on the same place.

On the right: in drawing placement of shtyrkovy conclusions of the sensor is shown.

On the right: in drawing the measuring instrument of a stream of fresh air, priflantsovanny to the air filter of naturally aspirated engines with a working volume of 1,6 and 1,8 l is shown.

1 – support of a termoanemometrichesky electroconductive plate;
2 – pass for air.

At the left: information on an arrangement of contacts of the triple-pole socket is used for check of the measuring instrument of a stream of fresh air in naturally aspirated engines with a working volume of 1,6 and 1,8 l.

On the right: at the turbo engine with a working volume of 1,8 l the measuring instrument of a stream of fresh air is integrated into the case of the air filter. The socket (2) is available from above.

At the left: information on distribution of contacts of the quadripolar socket is used when checking the measuring instrument of a stream of fresh air of the turbo engine with a working volume of 1,8 l.

Check of the sensor of temperature of cooling liquid

The sensor of temperature of cooling liquid is the device with double function which in one couple contacts provides with information system of ignition/injection, in other couple of contacts – the combined device. Here we check the knot connected with system of ignition/injection.

 PERFORMANCE ORDER

  1. Disconnect the sensor socket in a tube of supply of cooling liquid behind a head of the block of cylinders.
  2. Connect an ohmmeter to contacts "1" and "3" sockets of the sensor.
  3. Consider resistance size at the cooled-down engine and room temperature (about 20 °C).
  4. Nominal size: 1,5–3,0 kOhm.
  5. If nominal size is received, the sensor as it should be.

Check of the sensor of temperature of the soaked-up air

 PERFORMANCE ORDER

  1. Disconnect the socket on the sensor.
  2. Connect an ohmmeter to contacts of the socket of the sensor.
  3. Consider resistance size at the cooled-down engine and room temperature.
  4. Nominal size: 1,6–2,8 kOhm.
  5. If nominal size is received, the sensor as it should be.

Measuring instrument of a stream of fresh air

By own efforts it is possible to check giving of tension to the measuring instrument of a stream of fresh air and passing of a signal on wires to the control unit. If that and another as it should be, at defect in this knot (conduct survey of the computer) the measuring instrument of a stream of fresh air is considered faulty:

 PERFORMANCE ORDER

  1. Disconnect the socket on the measuring instrument of a stream of fresh air.
  2. Look at numbering of uvulas of contacts in drawing.
  3. Check of tension: at the 74 kW and 92 kW engine connect a diode test lamp between the 3 plug on the triple-pole socket of the connected wire and "weight" (the engine block).
  4. At the 110 kW turbo engine connect a diode test lamp between the 3 plug on the quadripolar socket of the connected wire and the weight (the engine block).
  5. Let your assistant will turn the engine a starter (the engine can even be started): the light-emitting diode has to flash, in this case tension moves.
  6. Check of passing of a signal: switch off ignition. Disconnect the socket "A" on the control unit.
  7. By means of an ohmmeter check conductivity of wires:
  8. With the 74 kW and 92 kW engines from a shtyrkovy conclusion "1" on the socket of the control unit "A" to contact "2" on the triple-pole socket of the measuring instrument of a stream of fresh air. Besides, from a shtyrkovy conclusion "9" on the socket of the control unit "A" to contact "3" on the triple-pole socket of the measuring instrument of a stream of fresh air.
  9. With the 110 kW turbo engine from a shtyrkovy conclusion "1" on the socket of the control unit "A" to contact "4" on the quadripolar socket of the measuring instrument of a stream of fresh air. Besides, from a shtyrkovy conclusion "9" on the socket of the control unit "A" to contact "2" on the quadripolar socket of the measuring instrument of a stream of fresh air.

Dismantle of valves of injection

 PERFORMANCE ORDER

  1. Dismantle facing of a motive compartment of the engine with a working volume of 1,6 l (head Dvigateli); with the engine of 1,8 l pull facing for back edge up in the beginning, then take out it from the forward party.
  2. Disconnect a vacuum hose from the fuel pressure regulator.
  3. For pressure decrease open for a short time a cover of a fuel tank.
  4. Weaken screw connection of the giving fuel-supply line. Be careful! Residual pressure! Opening the pipeline, cover it with a rag. Let the following fuel drip in a rag.
  5. Dismantle a recirculation fuel pipe.
  6. Disconnect sockets of valves of injection. For this purpose wring out at them on a reverse side wire clamps.
  7. At engines with a working volume of 1,8 l disconnect the Hall sensor socket.
  8. Unscrew both fixing bolts of a distributive tube of fuel.
  9. Pick up the distributive phone of fuel together with injection valves.
  10. If it is necessary to dismantle one valve of injection, remove a fixing collar and take out the valve from a distributive tube.
  11. At installation track that sealing rings and rubber rings of round section were replaced.
  12. When replacing a rubber ring of round section do not wring out a plastic cap on the valve at all.
  13. Before installation oil all rubber details. Insert valves together with a distributive tube.

Shtekerny sockets behind at the left in a motive compartment in the engine with a working volume of 1,6 l

1 – shtekerny socket lambda probe (black);
2 – shtekerny socket of a sensor of a detonation (green);

3 – shtekerny socket of the sensor of frequency of rotation of the engine (gray).

Shtekerny sockets behind at the left in a motive compartment in the engine with a working volume of 1,8 l

1 – shtekerny socket lambda probe (black);
2 – shtekerny socket of the sensor of frequency of rotation of the engine (gray);

3 – shtekerny socket of a sensor of a detonation I (green);
4 – shtekerny socket of a sensor of a detonation II (blue).