Audi A4

Since 1994 of release

Repair and car operation



Audi А4
+ Running gear
+ Regular servicing
+ Engines
+ Turbo-supercharging
+ Exhaust system
+ Cooling system
+ Fuel tank and the fuel pump
+ The air filter and channels всасывания
+ Injection system
+ Coupling
+ Transmission and the main transfer
+ Suspension bracket of wheels and steering
+ Brakes
+ Wheels and tyres
+ The electrotechnical equipment
- Ignition system
   That provides ignition
   When there is an ignition of a toplivno-air mix?
   Different systems of ignition
   So there is an ignition spark
   Executive office
   System brain
   The signals arriving in the block of management
   Detonation adjustment
   Be cautious in circulation with ignition
   Works on ignition system
   Search of malfunctions in ignition
   The ignition distributor
   High voltage knot
   Replacement of spark plugs
   Correct choice of spark plugs
   Check of the moment of ignition
+ Illumination
+ The alarm equipment
+ Tools and devices
+ Heating and ventilation
+ Body details
+ Salon
Search of malfunctions
Technical characteristics



Detonation adjustment

The detonation ignition arising in the event that the moment of ignition it is established with too big advancing, harms to the engine. Its consequence are an overheat, damages of bearings and pistons.

On the other hand, the biggest exit of capacity of the engine happens when the ignition moment is established with the maximum advancing, i.e. the engine rigidly works on detonation border. This border of a detonation is influenced by too numerous factors (quality of fuel, adjournment in combustion chambers and so forth) that it could be defined precisely in advance.

Therefore at traditional installation of ignition it is necessary to have big «safety distance» or «a supervision post» which establishes – if there is a detonation combustion – detonation regulation.

Function of adjustment of a detonation

Combustion in cylinders is supervised by a so-called sensor control of a detonation which is screwed at the left on the engine block. Two sensor controls are established in engines with working volume 1,8 l (at the left on the block) and in six-cylinder engines (on the right and at the left above on the block).

The detonation sensor control "feels", when combustion in cylinders instead of usual uniform fluctuations gives a picture of non-uniform fluctuations. The sensor control transfers this information in the electronic block of management.

There there is a following: at signal receipt «detonation combustion at last ignition» the following on turn cylinders continue to receive the moment of ignition calculated for them. But in that cylinder where the detonation has been established, the ignition moment moves approximately on 3 ° back. As it is noticed above, it occurs only in one cylinder. In others the moment of ignition calculated originally remains.

If detonation combustion in the given cylinder has remained, at a following working step the ignition moment again moves back on 3 °. It can be carried out a maximum to 15 ° (a reference point the nominal moment of ignition is).

If in the corresponding cylinder ignition occurs again normally through short time the ignition moment again moves towards an advancing. It becomes approximately on 0,5 °, then the pause in some working steps while again there is no displacement on 0,5 ° towards an advancing follows.

It proceeds until will reach originally planned moment of ignition or while the detonation sensor control again will not give a signal about detonation combustion.

Detonation sensor control

He listens, whether there is a detonation: the detonation sensor control is in four-cylinder engines on an engine left-hand side. In the six-cylinder engine is on one sensor control of a detonation (arrow) on the right and at the left above under an inlet collector. Important: fixing bolts of a sensor control of a detonation should be tightened precisely on 20 Nanometers, differently a sensor control will not work.

The slice is inserted into this sensitive element «пьезокерамики», a material which we well know on gas пьезозажигалкам. Mechanical forces (a stretching, pressure), operating on пьезокерамику, will be transformed by it to electric pressure.

To make active a sensor control, enough non-uniform fluctuations which are made by detonation combustion.