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Overview
Ignition system creates in each cylinder of the engine, at a certain moment, a spark that ignites the injected fuel mixture. For the formation of a spark in the ignition coil 12V battery voltage is converted into a high voltage ignition 25 000-30 000 V.
The ignition system basically consists of the ignition coil, spark plugs, ignition distributor with Hall sensor, control unit ignition TCI-H (TSZ - H), FEl (VEZ), Digifant, KE-Motronic. Carbureted engines as well as engines with fuel injection Mono-Jetronic, equipped with transistor ignition system TCI-H (TZS). Engine DOCH without catalyst, with letter designation KR has a transistor ignition system as an additional unit. This system is called the ignition FEl (VEZ). In engines with ignition and injection Digifant, developed by VW, FEl (VEZ) is built into the fuel injection system control unit and is equipped with an additional knock sensor. The system KE-Motronic firm BOSCH, installed on an engine with 2.0 liter DOCH catalyst has, in comparison with a system Digifant, only the control unit and the ignition-injection.
Ignition system TCI-H (TSZ - H)
| Fig. 6.3. Ignition system TCI-H (TSZ - H) 1 - Switch; 2 - high-voltage wires; 3 - tips suppression; 4 - screen; 5 - a cover of the distributor of ignition; 6 - coal contact; 7 - the spark plug; 8 - the tip of the spark plug; 9 - the ignition coil; 10 - a protective cover; 11 - Pin 1 (-); 12 - 15-pin connector (); 13 - terminal 4
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Transistor ignition system (Fig. 6.3) - a contactless ignition system. Instead breaker distributor is equipped with a maintenance-free sensor Hall. Capacitor ignition offline. Sensor - contactless, microelectronic, is based on the Hall effect (Fig. 6.4). This effect is the appearance of a transverse electric field in a current-carrying semiconductor plate, under the action of its magnetic field. The sensor includes (Fig. 6.5) of a permanent magnet and a semiconductor chip wafer. Between the plate and the magnet has a gap. The gap sensor is a steel screen with slots. When the slot passes through the gap screen, it acts on the plate of a semiconductor magnetic field and it is removed a potential difference. If the body is located in the gap screen, the lines of magnetic force closes through the screen and onto the plate does not operate. In this case, the potential difference between the plate arises. A separate electronic switch controls the low voltage circuit of the ignition coil.
| Fig. 6.5. The principle of operation of the sensor on the use of the Hall effect: 1 - steel screen with slits; 2 - magnets; 3 - Hall sensor; 4 - an air gap; b - width of the petal steel screen
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Ignition timing changes automatically spark occurs only in strictly defined depending on load and engine speed. The ignition timing is controlled vacuum regulator ignition timing. Vacuum controlled diaphragm, one side of which is connected via a tube to the intake manifold. Vacuum while the other side - on the baseplate. The vacuum in the inlet manifold varies according to the engine speed and the throttle opening degree, and causes the diaphragm to move. The diaphragm, in turn, moves the base plate, increasing or decreasing the ignition timing and, consequently, changes the ignition timing.
Ignition system FEl (VEZ)
| Fig. 6.6. Ignition system FEI (VEZ): 1 - the electrical connector; 2 - the gauge-switch of the throttle; 3 - Switch; 4 - the control unit; 5 - vacuum shlan; 6 - an electrical connector; 7 - connection with "weight", 8 - connection with "weight" of the control unit; 9 - high-voltage wire; 10 - the ignition distributor; 11 - a cover of the distributor; 12 - a cover of the noise blanker; 13 - terminal 1 (-); 14 - Terminal 4; 15 - tips; 16 - terminal 15 (+); 17 - connection with "weight" of the switch; 18 - the ignition coil; 19 - carbon contact; 20 - the ignition distributor rotor; 21 - dust cap; 22 - temperature sensor; 23 - an electric socket; 24 - a sealing ring; 25 - a bolt; 26 - a sealing ring; 27 - a spark plug; 28 - spark plug
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This transistor ignition system with electronic control unit (Fig. 6.6). The control unit electronically adjusts ignition timing that the system TCI-H (TSZ - H) is carried out thanks to the centrifugal and vacuum regulators.
The system of ignition and injection Digifant
| Fig. 6.7. The system of ignition and injection Digifant: 1 - the control unit (switch); 2 - an electric socket; 3 - mounting plate; 4 - a nut; 5 - the gauge-switch of the throttle; 6 - a bolt; 7 - knock sensor (cylinder block); 8 - a temperature sensor (blue); 9 - electric socket; 10 - a control unit Digifant
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In this system (Fig. 6.7), an electronic ignition control and fuel injection is integrated into one control unit. Ignition system transistor with a Hall sensor and an electronic control unit determines the ignition timing. The device of the ignition system Digifant basically corresponds to the ignition system FEl (VEZ), however, an additional ignition timing is adjusted also for the signal knock sensor that is sensitive to premature ignition and thus reduces the ignition timing.
The system of ignition and injection KE-Motronic
| Fig. 6.8. The system of ignition and injection KE-Motronic: 1 - the spark of healing; 2 - O-ring; 3 - ground plate on the cylinder head; 4 - the throttle body; 5 - a bolt; 6 - dust cap; 7 - electric socket; 8 - distributor rotor; 9 - control unit; 10 - high-voltage wires; 11 - electrical connectors; 12 - One-contact electrical connector; 13 - a protective cover; 14 - the ignition coil; 15 - tips; 16 - the gauge on the high-voltage wire 4-cylinder; 17 - a cover of the noise blanker; 18 - a cover of the distributor, 19 - carbon contact; 20 - the ignition distributor; 21 - the gauge of a detonation 2; 22 - a bolt; 23 - the gauge of a detonation 1; 24 - a spark plug
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| Fig. 6.9. Location knock sensors on engine block 1 - wire; 2 - the gauge of a detonation 2; 3 - a bolt; 4 - the gauge of a detonation 1
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| Fig. 6.10. Location torque sensor plugs: 1 - high-voltage wire 4-cylinder; 2 - an electric socket; 3 - the gauge of the moment of ignition
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The system KE-Motronic (Fig. 6.8.) BOSCH same manner as in Digifant, ignition control and fuel injection is performed by one common control unit 9. The ignition distributor 20 with the Hall sensor is the same as in the FEI (VEZ). The control unit, however, has its own additional diagnostics, which means that a fault occurring in the ignition system and fuel injection, stored in the memory of the control unit, which can be queried and decrypted fault will purposefully removed. Unit power as compared with other systems, ignition, situated next to the ignition coil 14 and is designed to adjust the current signal for the ignition coil unit. KE-Motronic system features two knock sensor 2, 4 (Fig. 6.9), which define a detonation in each cylinder and automatically change the time for them to switch. Additional inductive sensor 3 (Fig. 6.10) includes a high-voltage ignition timing wire 1 of the fourth cylinder and the control unit delivers the ignition signal at the time of ignition, which is required to analyze the sensor signals detonation. The ignition distributor mounted in the cylinder block on engines SOHC, and on the engines DOHC installed on the rear of the cylinder head and is driven by the camshaft operating final valves.
Possible malfunctions of the generator, their causes and remedies
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