Ignition system generates a spark in each cylinder at a time. It ignites the fuel-air mixture supplied. For this purpose, the ignition coil voltage of the battery 12 is converted into a voltage of 25 000-30 000 V. Electronic control unit engine control system has a memory for recording the fault codes that arise in the ignition system while driving. Before repair the ignition system must first be considered fault codes from the control unit. Questioning the control unit is carried out by a special device through the diagnostic connector located under the dashboard.
Security measures at work with elements of the electronic ignition system
The voltage at the high voltage side of the ignition system is up to 30 kV. Under unfavorable circumstances, such as at high humidity in the engine compartment, power surges can penetrate the insulation, which if touched can cause electrical accident. to avoid injury and / or damage to the electronic ignition system, when working on vehicles with electronic ignition must adhere to the following rules:
- Before cranking the starter (for example, when checking the compression), turn off the ignition and disconnect the connector from the power amplifier, which is located on the ignition coil;
- Do not touch or disconnect the high voltage wires of the ignition system with the engine running or cranking the starter motor;
- Disconnect the wires of the ignition system only when the ignition is off;
- To carry out connection and disconnection of control instruments (tachometer and Spark Tester) only when the ignition is switched off;
- When towing the car, which in the ignition system fault has occurred or is expected of her presence, disconnect the wire from the power amplifier;
- Allowed for engine start
1 min using a quick charger maximum voltage of 16.5 V. After each start attempt should be made a break of not less than 1 min;
- The ignition coil can not be replaced by another model coil or modifying the vehicle with another motor. In no case can not be installed from the contact ignition coil ignition system;
- Complete disconnection of the battery can be carried out only when the ignition is switched off, otherwise you can damage the control unit of the ignition system;
- To carry out cleaning of the engine only when the ignition is switched off;
- With an electronic ignition system should not be used by persons with pacemakers;
- After heating to a temperature above +80 ?° C (for example, when painting work) does not start up the engine immediately after heating;
- When working with electricity and spot welded completely disconnect the battery;
- Do not apply to the control voltage to simulate output.
Elements of system of ignition
Fig. 7.28. Location in the engine compartment components ignition engine with two camshafts in the cylinder head (DOHC): 1 - high voltage wires; 2 - spark plugs; 3 - ignition coil
Fig. 7.29. Location in the engine compartment components ignition engines with a single camshaft in the cylinder head (SOHC): 1 - the ignition coil; 2 - high voltage wires
Location in the engine compartment components ignition engine with two camshafts in the cylinder head (DOHC) shown in Fig. 7.28. Location in the engine compartment components ignition engines with a single camshaft in the cylinder head (SOHC) shown in Fig. 7.29.
Remove the ignition fuse (fuse box).
Disconnect the wires.
Fig. 7.30. Mount the ignition coil engine displacement of 1.1 liters
Fig. 7.31. Mount the ignition coil motors working volume of 1.3, 1.5 and 1.6 liters
Installation spend in the reverse order of removal.
Fig. 7.32. Check the resistance of the primary winding of the ignition coil 1 - ignition coil second and third cylinders; 2 - the coils of the first and fourth cylinders
Check the resistance of the primary coil windings between the terminals "1" and "2" (Fig. 7.32).
Check the resistance of the secondary winding of the coils between the high-voltage output coil first and fourth cylinders and high-voltage outputs second and third cylinders.
Fig. 7.33. Check the resistance of the secondary winding of the ignition coil
Rated secondary resistance ignition coils (13 ?± 15) k (Fig. 7.33).
Check the resistance of the secondary windings is carried out only when disconnected, ignition coils.
Car manufacturers recommend the use of spark plugs
a particular type, but you can use other suitable types of candles and with the appropriate heat range.
Spark plugs need to be cleaned by sandblasting every 10 000 km of run of the car. This should set the appropriate electrode spacing. When adjusting the distance never to buckle the central electrode as it can break the ceramic insulator.
Before loosening the spark plug, check that the wells of candles in the cylinder head there are no objects. Caught in the hole candles washers, bolts or small stones destroy valves, valve seats and cylinder head at the first engine start-up. Spark plug comprises a central electrode with an insulator body and a side electrode "mass". The central electrode is sealed in an insulator. Last strongly associated with the case. Between the central and lateral electrodes slips spark, igniting fuel-air mixture in the cylinder. From spark plugs depend on the quality of the engine starting, the nature of his idling, acceleration and top speed. It is therefore not recommended without special reason to move from the candles recommended by the manufacturer, to spark another type. Thermal performance (heat rating) candle is a measure of the degree of heat stress in the engine spark under certain conditions. Candles are selected so that under all possible operating conditions of the car, they reach a temperature of self-cleaning. The lower the number of candles glow, the greater its resistance to surface ignition and the less resistance to contamination. The higher heat rating, the lower the resistance to surface ignition spark and the higher its resistance to contamination.
Heat range is contained in the designation of a candle.
Fig. 7.34. The tip of the high-voltage wire ignition engines with a single camshaft in the cylinder head (SOHC)
Fig. 7.35. The tip of the high-voltage wire ignition engine with two camshafts in the cylinder head (DOHC)
To avoid damage to the high-voltage wires, remove it by pulling the tip of the wire, not the cord (see. Fig. 7.34 and 7.35)
Spark plug wrench, remove the spark plug all of the cylinder head.
Make sure that the cylinder through the spark plug socket for not hit dirt.
Check the spark plug for the following defects:
Fig. 7.36. Places visual inspection of the state of the spark plug
- Burning electrodes (point 2);
- Fouling (point 3);
- Damage the gasket (point 4);
- Damage to the porcelain insulator at the end of the spark (point 5).
Fig. 7.37. The gap (A) between the electrodes of the spark plug
Check the dipstick and, if necessary, adjust the clearance A (Fig. 7.37) between the electrodes of the spark plugs.
The nominal value of the gap between the electrodes of a spark plug (when using unleaded petrol) 1.0-1.1 mm.
Replace the spark plugs by hand and tighten to 20-30 Nm.
Over-tightening spark can cause damage to the thread sockets for candles.
Determining the state of the engine in appearance spark plugs
Engine condition can be estimated by the color of soot on the spark plug electrodes.
Check spark plugs (with the possibility of cranking the engine)
Fig. 7.38. Driving checking the spark plugs while cranking the engine starter motor (ignition on): 1 - the ignition coil; 2 - the spark plug; 3 - the ignition switch; 4 - Electronic control unit
Driving checking the spark plugs while cranking the engine starter motor (ignition switched on) is shown in Fig. 7.38.
Attach the wire to the spark plug. Connect the outer electrode spark (housing) to "weight" and turn the crankshaft. Due to the low ambient pressure produced only short sparks. However, if the candle is serviceable, sparking should occur in the spark gap spark (between the electrodes). When a faulty spark sparking will not be due to the leakage current through the insulator.