The system of ignition develops in each cylinder a spark at a given time. It ignites a submitted toplivovozdushny mix. For this purpose in the ignition coil tension of the storage battery 12 B will be transformed to tension of 25 000–30 000 Century. The electronic control unit of a control system of the engine is equipped with memory for record of codes of the malfunctions arising in system of ignition during movement of the car. Before repair of system of ignition it is necessary to consider at first codes of malfunctions from memory of the control unit. Poll of memory of the control unit is carried out by the special device via the diagnostic socket being under the dashboard.
Security measures at works with elements of electronic system of ignition
Tension in a high-voltage part of system of ignition makes to 30 quarter. Under adverse circumstances, for example at the increased humidity in a motor compartment, power surges can punch isolation that at a contact can lead to an electrotrauma. to avoid traumas and/or damages of electronic system of ignition, at works on cars with electronic ignition it is necessary to adhere to the following rules:
– before a provorachivaniye of a cranked shaft a starter (for example, at compression check) switch off ignition and disconnect the contact socket from the amplifier of capacity located on the coil of ignition;
– do not touch by hands and do not disconnect high-voltage wires of system of ignition on the working engine or at a provorachivaniye of a cranked shaft of the engine a starter;
– disconnect wires of system of ignition only at the switched-off ignition;
– carry out connection and shutdown of control devices (a tachometer and an ignition tester) only at the switched-off ignition;
– at car towage which ignitions in system had a malfunction or its existence is supposed, it is necessary to disconnect a wire from the amplifier of capacity;
– engine start-up is allowed during
1 mines by means of the fast-charger it is necessary to do by 16,5 V.Posle's maximum tension of each attempt of start-up a pause lasting not less than 1 mines;
– it is impossible to replace the coil of ignition with the coil from other model or car updating with other engine. By no means it is impossible to establish the ignition coil from contact system of ignition;
– the blackout of the storage battery can be carried out only at the switched-off ignition, differently it is possible to damage the control unit of system of ignition;
– carry out a wash of the engine only at the switched-off ignition;
– with electronic system of ignition persons with electropacemakers should not work;
– after heating to temperature more than +80 °C (for example, at painting works) do not start up the engine directly after heating;
– at work with electro - and spot welding completely disconnect the storage battery;
– do not put to the control unit tension for imitation of a target signal.
Elements of system of ignition
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Fig. 7.28. An arrangement in a motor compartment of elements of system of ignition of engines with two camshafts in a head of the block of cylinders (DOHC): 1–wires of a high voltage; 2–spark plugs; 3–ignition coil
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Fig. 7.29. An arrangement in a motor compartment of elements of system of ignition of engines with one camshaft in a head of the block of cylinders (SOHC): 1–ignition coil; 2–wires of a high voltage
|
The arrangement in a motor compartment of elements of system of ignition of engines with two camshafts in a head of the block of cylinders (DOHC) is shown on
fig. 7.28
. The arrangement in a motor compartment of elements of system of ignition of engines with one camshaft in a head of the block of cylinders (SOHC) is shown on
fig. 7.29
.
Ignition coil
Removal and installation
Remove a safety lock of system of ignition (a fusible insert).
Disconnect wires.
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Fig. 7.30. Fastening of the coil of ignition of engines in working volume of 1,1 l
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Fig. 7.31. Fastening of the coil of ignition of engines in working volume 1,3, 1,5 and 1,6 l
|
Remove the ignition coil, having unscrewed a fastening bolt (fig. 7.30 and 7.31)
.
Installation carry out as it should be, the return to removal.
Check of a technical condition
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Fig. 7.32. Check of resistance of primary winding of the coil of ignition: 1–coil of ignition of the second and third cylinders; 2–coil of ignition of the first and fourth cylinders
|
Check resistance of primary winding of coils between contacts «1» and «2» (fig. 7.32)
.
Check resistance of a secondary winding of coils between high-voltage conclusions of the coil of the first and fourth cylinders and high-voltage conclusions of the second and third cylinders.
|
Fig. 7.33. Check of resistance of a secondary winding of the coil of ignition
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Nominal resistance of a secondary winding of coils of ignition (13±15) kiloohm (fig. 7.33)
.
PREVENTION
Check of resistance of secondary windings carry out only at the disconnected socket of coils of ignition.
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Spark plugs
Producers of cars recommend application of spark plugs
a certain type, but it is possible to use suitable candles and other types with the corresponding kalilny number.
Spark plugs should be cleared by means of the peskostruyny device through each 10 000 km of run of the car. Thus it is necessary to establish the corresponding interelectrode distance. At distance adjustment never turn in the central electrode as its ceramic insulator can burst.
Before an otvorachivaniye of spark plugs check, that in wells of candles in a head of the block of cylinders there were no extraneous subjects. Got to openings of candles of a washer, bolts or small stones will destroy valves, saddles of valves or a head of the block of cylinders at the first start-up of the engine. The spark plug consists of the central electrode, an insulator with the case and a lateral electrode of "weight". The central electrode is tightly established in an insulator. The last is strongly connected with the case. Between central and lateral electrodes the spark of ignition igniting a toplivovozdushny mix in the cylinder of the engine slips. Starting qualities of the engine, nature of its work depend on a spark plug idling, acceleration performance and the maximum speed of the car. Therefore it is not recommended to pass without the special reasons from the candles recommended by manufacturer, to candles of other type. The thermal characteristic (kalilny number) candles is an exponent of thermal loading of a candle in the engine under certain conditions operation. Candles select so that under all possible service conditions of the car they reached self-cleaning temperature. The kalilny number of a candle, the higher it resilience to kalilny ignition and the less its resistance to pollution is lower. The kalilny number is higher, the resilience of a candle to kalilny ignition and the higher it resistance to pollution is lower.
Kalilnoye number contains in candle designation.
Removal
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Fig. 7.34. A tip of a high-voltage wire of system of ignition of engines with one camshaft in a head of the block of cylinders (SOHC)
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Fig. 7.35. A tip of a high-voltage wire of system of ignition of engines with two camshafts in a head of the block of cylinders (DOHC)
|
Disconnect wires from spark plugs (fig. 7.34 and 7.35)
.
NOTE
In order to avoid damage of a high-voltage wire disconnect it, having pulled for a wire tip, instead of for a wire (see
fig. 7.34 and 7.35
)
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Candle key turn out all spark plugs from a head of the block of cylinders.
PREVENTION
Track that pollution did not get to cylinders through nests under spark plugs.
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Check of a technical condition
Check spark plugs on existence of the following defects:
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Fig. 7.36. Places of visual check of a condition of a spark plug
|
– insulator damage (a point 1 on
fig. 7.36
);
– burning out of electrodes (point 2);
– deposit (point 3);
– laying damage (point 4);
– damage of a porcelain insulator on the candle end (a point 5).
|
Fig. 7.37. A gap (And) between spark plug electrodes
|
Check shchupy and if necessary adjust a gap And (fig. 7.37)
between electrodes of spark plugs.
Nominal rate of a gap between spark plug electrodes (when using unleaded gasoline) 1,0–1,1 mm.
Screw spark plugs a hand and tighten the moment of 20-30 N · m.
The excessive inhaling of candles can lead to damage of a carving of nests under candles.
Definition of a condition of the engine on appearance of spark plugs
The condition of the engine can be estimated on color of a deposit on electrodes of spark plugs.
Check of spark plugs (at possibility of a provorachivaniye of a cranked shaft of the engine)
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Fig. 7.38. The scheme of check of a spark plug at a provorachivaniye of a cranked shaft of the engine a starter (ignition is included): 1–ignition coil; 2–spark plug; 3–ignition switch; 4–electronic control unit
|
The scheme of check of a spark plug at a provorachivaniye of a cranked shaft of the engine is shown by a starter (ignition is included) on
fig. 7.38
.
Attach a wire to a spark plug. Connect an external electrode candles (case) to "weight" and turn a cranked shaft. Owing to small pressure of environment only short sparks are formed. However, if the candle is serviceable, the iskroobrazovaniye should occur in a spark interval of a candle (between electrodes). At a faulty candle of an iskroobrazovaniye will not be because of leakage of a current through an insulator.