Audi A3

Since 1997 of release

Repair and car operation



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





System of injection of fuel

The general information and security measures

THE GENERAL DATA

Arrangement of elements of a control system of engine Simos. Engines of 1.6 l

1 - a socket
For the gauge of the Hall (black)
2 - the Hall gauge
Under the top cover of a gear belt
3 - the oxygen gauge, 50 Н
Position at АТ: in a final collector
4 - a socket
For the oxygen gauge, from the bottom party of the car on the right
5 - the valve of switching of the inlet pipeline
6 - monitor Simos
7 - the block of management throttle заслонкой
8 - the gauge of temperature of a cooling liquid
9 - a measuring instrument of weight of air
With the gauge of temperature of soaked up air
10 - joining of weight at РКПП
11 - ignition coils
With a step of target capacity
12 - a socket
For the detonation gauge
13 - the gauge of number of turns of the engine
14 - a socket
For the gauge of number of turns of the engine (black)
15 - the detonation gauge
16 - injectors
17 - a regulator of pressure of fuel
18 - an adsorber
19 - the electromagnetic valve of an adsorber

Arrangement of elements of a control system of engine Motronic. The engine of 1.8 l (125 h.p.)

1 - the electromagnetic valve for an adsorber
2 - a socket
For the gauge of oxygen (black)
3 - the gauge of temperature of soaked up air
4 - the block of management throttle заслонкой
5 - monitor Motronic
6 - the valve of adjustment of a camshaft
7 - a measuring instrument of weight of air
8 - the gauge of temperature of a cooling liquid
9 - a regulator of pressure of fuel
10 - injectors
11 - ignition coils, a target step
12 - the gauge of number of turns of the engine
13 - the gauge of a detonation 2
14 - a socket
For the gauge of a detonation 2.
15 - the gauge of a detonation 1
16 - a socket
For the gauge of number of turns of the engine.
17 - a socket
For the gauge of a detonation 1.
18 - the Hall gauge
Instructions: About 8/97 releases the adjustable pipe of an admission with the switching valve is in addition established.

The electronic control system of the engine regulates quantity of fuel submitted to cylinders and operates ignition process. At petrol engines of car AUDI A3 various control systems are applied.

The electronic control system of the engine provides following possibilities:

– An exact dosage of fuel in any mode of operation that provides the small expense of fuel at high capacity.
– Reduction of the maintenance of harmful substances in the fulfilled gases thanks to exact dispensing of fuel and application каталитического the converter.
– Self-diagnostics of a control system by the engine that provides possibility of fast troubleshooting. The control system of the engine has memory of malfunctions. If defect it is brought in memory of the device while in service comes to light. If in the engine there are malfunctions there is a possibility to deduce on the printer the list of the malfunctions, allowing to reveal and eliminate defect independently.

The engine management block represents the microprocessor with high speed. It defines optimum time of injection and quantity of injected fuel. Thus there is a coordination of work of the block of management with other systems of the car, for example, to control system РКПП or blocking from stealing.

Elements of a control system of the engine keeps the high working capacity for a long time and practically does not demand service. Replacements at carrying out of maintenance service demand only the air filter and spark plugs. Serious works on adjustment and repair demand application of difficult diagnostic devices. Their carrying out is possible only in conditions HUNDRED.

Adjustment of number of turns of idling and concentration WITH within the limits of maintenance service carrying out is not required.

Security measures at work with a control system of the engine / the petrol engine

The fuel system is under pressure! At system opening fuel emission is possible. Therefore the flowed out fuel is necessary for wiping a rag. Gasoline steams are poisonous and горючи. Use goggles. Watch good ventilation of a workplace. Have on call the fire extinguisher.

For an exception травмирования and-or damages of system of injection and ignition the following is necessary to observe people:

– Do not concern and do not disconnect ignition wires at the working engine or at the included starter.
– Disconnect and attach pipelines of system of injection and an ignition wire, and also electric wires of devices of measurement only at the switched off ignition.
– It is not necessary to work with electronic system of ignition to people with a warm stimulator.
– At compression check fuel injection is not supposed.

ATTENTION

At work with injection system it is necessary to observe the general safety rules and cleanliness.



Remarks on check of a control system by the engine

– For search of malfunctions, first of all, it is necessary to deduce indications from memory of malfunctions and to check up on tightness vacuum joinings.
– For reliable functioning of all electric elements of system presence of pressure not less is necessary than 11.5 Century
– If after search of malfunctions, carrying out of repair or check of details it is started only for short time, and then stops, the reason can be that the anticreeping system is blocked. For this purpose it is necessary to interrogate memory of malfunctions and if necessary to adjust a monitor.

Work of system of injection of the petrol engine

Fuel from a fuel tank is sucked in by an electric gasoline pump and moves through the fuel filter located on a floor of the car to injectors. The pressure regulator supports constant pressure in fuel system.
Through электрически operated injectors fuel порционно moves in a corresponding inlet pipe directly ahead of inlet valves of the engine. The engine management block operates duration of injection and by that quantity of injected fuel.

Air which is sucked in in the engine, passes the air filter, arrives through throttle заслонку and soaking up pipe to inlet valves.

The weight of soaked up air defines quantity of injected fuel. The weight of soaked up air is measured by a special measuring instrument. In the measuring instrument case there is thin, электрически a heated up sensitive plate–1 which is cooled by a stream of air passing through it. For maintenance of constant temperature of a sensitive plate the current size changes according to weight of sucked in air. The current size specifies to the block of management degree of loading of the engine and by that regulates quantity of injected fuel.

Arrangement of a film conductor 1 in a measuring instrument of weight of air


The information arriving from various gauges and a command, arriving to executive powers, provides optimum work of the engine in various service conditions. If gauges fail, the management block is switched to the emergency program to exclude damages of the engine and to provide possibility of the further movement of the car. Failure of gauges not necessarily should to affect engine work negatively. However at the nearest control of structure of the fulfilled gases it is necessary to consider indications of memory of malfunctions of a control system as the engine.

Gauges and executive mechanisms of engine management


Throttle заслонка it is located in the central block of management where the information from various gauges is concentrated. The primary goal of the block of management is stabilisation of a mode of idling at all power setting and loading conditions. The idling switch hands over to the block of management the information on position of idling throttle заслонки. The management block through the electric motor opens or closes throttle заслонку, regulating, thus, number of turns of idling.

– The gauge of temperature of a cooling liquid and the gauge of temperature of soaked up air hand over in the block of management the information on current value of temperatures on the basis of change of value of their electric resistance. At increase of temperature resistance decreases.

– The system of ventilation of a fuel tank consists of an adsorber and the electromagnetic valve. In an adsorber steams of gasoline formed in a tank owing to heating of fuel collect. At the working engine of pair gasoline are sucked away from an adsorber and move in the engine.

– The oxygen gauge measures the oxygen maintenance in the fulfilled gases and transmits a corresponding signal in the engine management block.

– The detonation gauge serves for definition of the optimum moment of ignition. At malfunctions of ignition fuel giving to corresponding cylinder stops.

Engines of h.p. of 1.8 l/125 with 8/97, engines of 1.6 l have the adjustable inlet pipeline which depending on number of turns of the engine changes parametres of a soaking up path. For this purpose in the inlet pipeline it is established заслонка with a pneumatic drive. The long pipeline at low number of turns thanks to resonant effect provides good filling of cylinders and by that a high twisting moment. At high number of turns of the engine the inlet pipeline is shortened that provides fuller use of potential of capacity of the engine.

Engines of h.p. of 1.8 l/125: For reception of optimum capacity and an engine twisting moment in a wide range of turns there is a mechanism of regulation of the moment of opening and closing of inlet valves depending on number of turns. Usually opening and closing time is defined by a camshaft configuration. For maintenance вариативной adjustments of cams, camshafts of inlet and final valves are connected with each other by a chain. The hydraulic mechanism of adjustment, depending on engine turns, displaces a point of turn of a chain in a branch of connection of gear wheels of cam-shafts. Thanks to it phases of work of inlet valves in relation to the final are displaced. For twisting moment increase in a range from low to average turns the adjustment mechanism joins, and the camshaft of inlet valves opens and closes valves earlier.

Checks of system of injection of fuel – the general data


In system of injection of fuel it is independently possible to check up only the basic electric chains.

If normal work of the engine is broken, first of all check up a condition of electric conducting and sockets. Check up a condition of a filtering element of the air filter, and also a condition and an interelectrode backlash of spark plugs. Check up passableness of hoses of ventilation картера the engine and adjustment of a cable of an accelerator. If the engine still works unstably, check up a compression in engine cylinders.

If there is a suspicion for bad work of an injector, clean it.

If the engine still works unstably, check up elements of system of ignition.

If malfunction is not eliminated yet, check up integrity of fuses and a condition of electric sockets and electroconducting. On electric sockets there should not be melted off contacts, a moisture, traces of corrosion, a dirt and other damages.

After carrying out of independent check address on specialised station "AUDI" for diagnostics of system of injection of fuel on the special equipment.
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