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3.34. Check / adjustment of installation of a corner of an advancing of ignition

General information

Corner of an advancing of ignition is called the corner on which the bent shaft between the moments of ignition of mix in each next cylinder turns. Measurement is performed concerning VMT of the end of a step of compression of the corresponding piston, the result is expressed in corners to or after VMT

Ideally ignition of air-fuel mix in the combustion chamber of the cylinder has to be made at the time of passing by the piston of provision of VMT of the end of a step of compression. At the same time vzryvoobrazno the increasing pressure in the cylinder will push the piston down, causing thereby rotation of a bent shaft of the engine. In view of the fact that sparking between electrodes candle/ignition of mix takes some time (fractions of a second), ignition has to be made the achievement moment by the piston of provision of VMT a little earlier, otherwise the maximum pressure pushing the piston will not be reached that will lead to decrease in the torque developed by the engine.

If to establish an ignition advancing corner on 10 ° before VMT, then ignition of air-fuel mix in each of cylinders will happen at the moment when the corresponding piston reaches the corresponding position (10 ° before VMT of the end of the step of compression). Told remains true only in operating time of the engine on single turns. To achieve maximum efficiency of return of engine/economy of fuel consumption it is possible to achieve if process of combustion of mix in cylinders comes to the end within 23 ° after VMT of the corresponding piston.

In process of increase of turns of the engine pistons begin to move quicker, at the same time spark plugs have to make ignition of air-fuel mix so that its combustion happened even a little before the moment when the corresponding piston reaches the provision of VMT. At installation of too early ignition the increasing pressure in the cylinder will interfere with advance of the piston up that leads to emergence of the characteristic knock, in a popular speech called by a detonation. Too late ignition as it was already told above, leads to noticeable decrease in efficiency of return of the engine.

On a rim of a pulley of a bent shaft and a cover of the GRM drive special adjusting tags are provided. At the same time the tag on a pulley corresponds to the provision of VMT of the end of a step of compression of the piston of the first cylinder to which wire of a spark plug it is necessary to connect a stroboscope when checking/adjustment installation of a corner of an advancing of ignition (watch that the electrical wiring of connection of a stroboscope did not concern cooling system fan blades!). At the same time flashes of a lamp will synchronously happen to the sparking moments between electrodes of this candle. Having directed a stroboscope beam to a pulley rim, it is possible to define easily position of the piston of the first cylinder at the time of the beginning of ignition of mix, - the tag on a rim of a pulley "will stand" opposite to the corresponding division fixed on a scale GRM drive cover. During adjustment of an advancing of ignition it is necessary to achieve compliance to requirements, standard for this model of the car (see further).

Check and adjustment

Model 1990-1996 of of the issue.

 PERFORMANCE ORDER

1. Cock the parking brake, start the engine and warm up it up to the normal working temperature. Disconnect everything onboard consumers of the electric power, bring forward wheels of the car into rectilinear situation. Include neutral transfer (models with RKPP) / transfer the selector lever to situation "P" (models from AT).
2. Make sure of correctness of installation of turns of idling.

3. Kill the engine, remove an antispray cover from the socket of adjustment of a corner of an advancing of ignition. By means of a wire crossing point ground the socket plug on weight.

4. Connect a tachometer, connect a stroboscope to VV to a wire of a spark plug of the first cylinder. Start the engine and leave it working at single turns.
5. Direct a stroboscope beam to the adjusting scale fixed near a pulley of a bent shaft.
6. Weaken fastening of the distributor of ignition / a clamping nut of the sensor of an angle of rotation of a bent shaft.
7. Rotating the distributor/sensor case, achieve the required adjusting value for an ignition advancing corner, then tighten fixture and kill the engine.
8. Remove a wire crossing point and install an antispray cover on the socket.
9. Start the engine and repeat check, without grounding of the socket this time, - the indication has to be displaced approximately on 5 ° towards increase in rather basic installation. The control unit of the engine can make correction of a corner of an advancing of ignition for a concrete combination of input parameters.
10. Kill the engine, disconnect a stroboscope and a tachometer.


Model 1997-2000 of of the issue.

 PERFORMANCE ORDER

On these models installation and adjustment of a corner of an advancing of ignition is made automatically under managements of the electronic module (ESM). Check can be made by means of the special diagnostic reader (scanner).