The system of ignition creates in each cylinder of the engine, at some point, the spark category which ignites, an injected fuel mix. For formation of a spark, in the ignition coil tension of the battery 12В will be transformed to a high voltage of ignition of 25 000–30 000 Century.

The ignition system generally consists from: coils of ignition, spark plugs, the ignition distributor with the sensor of the Hall, the control unit ignition of TCI-H (TSZ — N), FEl (VEZ), Digifant, KE-Motronic. 

Carburetor engines, as well as engines with system of injection of Mopo-Jetronic fuel, are supplied with transistor system of ignition of TCI-H (TZS).

The DOCH engine without the catalyst, with an alphabetic reference of KR has transistor system of ignition in the form of the additional block. This system of ignition is called as FEl (VEZ).

At engines with system of ignition and injection of Digifant developed by VW, FEl (VEZ) it is built in the control unit of system of injection and it is supplied in addition with the detonation sensor.

In KE-Motronic system of the BOSCH firm established on the engine of 2,0 l of DOCH with the catalyst, is available, in comparison with Digifant system, only the control unit ignition and injection.

System of ignition of TCI-H (TSZ — N)

Fig. 6.3. System of ignition of TCI-H (TSZ — N): 1–switchboard; 2–high-voltage wires; 3–tips of suppression of hindrances; 4–screen; 5–cover of the distributor of ignition; 6–coal contact; 7–spark plug; 8–spark plug tip; 9–ignition coil; 10-protective cover; 11-the contact socket 1 (–); 12-contact socket 15 (+); 13-plug 4

Fig. 6.4. Effect of the Hall

The transistor system of ignition (fig. 6.3) is a contactless system of ignition. Instead of the breaker the distributor of ignition is supplied with the sensor of the Hall not demanding leaving. The condenser of ignition is absent. The sensor — contactless, microelectronic, is based on use of effect of the Hall (fig. 6.4) . This effect consists in emergence of cross-section electric field in a semiconductor plate with a current, at action on it a magnetic field. The sensor consists (fig. 6.5) of a constant magnet, a semiconductor and chip plate. Between a plate and a magnet there is a gap. In a gap of the sensor there is a steel screen with cuts. When through a gap passes a screen cut, the plate of the semiconductor is affected by a magnetic field and from it the potential difference acts in film. If in a gap there is a screen body, magnetic power lines become isolated via the screen and a plate do not affect. In this case the potential difference on a plate does not arise. The separate electronic relay operates a chain of a low voltage of the coil of ignition.

Fig. 6.5. A principle of operation of the sensor on use of effect of the Hall: 1–the steel screen with cuts; 2–magnets; 3–Hall sensor; 4–air gap; b — width of a petal of the steel screen

The corner of an advancing of ignition changes automatically, the spark of ignition occurs only in strictly certain depending on loading and engine turns. The advancing of ignition copes a vacuum regulator of an advancing of ignition. The vacuum operates a diaphragm which one party is connected through a tube to an inlet collector. Razryazheniye and other party — to a basic plate. Depression in an inlet collector changes depending on turns of the engine and extent of opening of a butterfly valve, and forces a diaphragm to move. The diaphragm in turn moves a basic plate, increasing or reducing a corner of an advancing of ignition and, as a result, changes the ignition moment.

System of ignition of FEl (VEZ)

Fig. 6.6. System of ignition of FEI (VEZ): 1–electric socket; 2–butterfly valve sensor switch; 3–switchboard; 4–control unit; 5–vacuum шлан; 6–electric socket; 7–connection with "weight", 8 – connection with "mass" of the control unit; 9–high-voltage wire; 10-ignition distributor; 11-distributor cover; 12-interference suppressor cover; 13-the plug 1 (–); 14-plug 4; 15-tips; 16-plug 15 (+); 17-connection with "mass" of the switchboard; 18-ignition coil; 19-coal contact; 20-rotor of the distributor of ignition; 21-dustproof cap; 22-temperature sensor; 23-electric socket; 24-sealing ring; 25-bolt; 26-sealing ring; 27-spark plug; 28-spark plug tip

It is transistor system of ignition with the electronic control unit (fig. 6.6) . The control unit corrects in the electronic way the ignition moment that in TCI-H (TSZ — N) system is carried out thanks to centrifugal and vacuum regulators.

System of ignition and Digifant injection

Fig. 6.7. System of ignition and Digifant injection: 1–control unit (switchboard); 2–electric socket; 3–assembly panel; 4–nut; 5–butterfly valve sensor switch; 6–bolt; 7–the detonation sensor (on the block of cylinders); 8–sensor temperatures (dark blue); 9–electric socket; 10-Digifant control unit

In this system (fig. 6.7) electronic control by ignition and injection is incorporated in one control unit. Ignition system transistor with the sensor of the Hall and the electronic control unit defining the moment of ignition. The device of system of ignition of Digifant generally corresponds to system of ignition of FEl (VEZ), however, in addition the moment of ignition is corrected also on a signal of the sensor of a detonation which is sensitive to premature ignition and respectively reduces a corner of an advancing of ignition.

System of ignition and KE-Motronic injection

Fig. 6.8. System of ignition and KE-Motronic injection: 1–tip of a candle of mending; 2–sealing ring; 3–a grounding plate on a head of the block of cylinders; 4–butterfly valve case; 5–bolt; 6–dustproof cap; 7–electric socket; 8–distributor rotor; 9–control unit; 10-high-voltage wires; 11-electric sockets; 12-one-contact electric socket; 13-protective cover; 14-ignition coil; 15-tips; 16-the sensor on a high-voltage wire of the 4th cylinder; 17-interference suppressor cover; 18-a distributor cover, 19 – coal contact; 20-ignition distributor; 21-sensor of a detonation 2; 22-bolt; 23-sensor of a detonation 1; 24-spark plug

Fig. 6.9. An arrangement of sensors of a detonation on the block of cylinders: 1–wire; 2–sensor of a detonation 2; 3–bolt; 4–sensor of a detonation 1

Fig. 6.10. Arrangement of the sensor of the moment of ignition: 1–high-voltage wire of the 4th cylinder; 2–electric socket; 3–sensor of the moment of ignition

In KE-Motronic system ( fig. 6.8 .) BOSCH as well as in Digifant, management of ignition and injection is carried out by one general control unit 9. The distributor of ignition 20 with the sensor of the Hall same, as well as in FEI (VEZ). The control unit, however, has in addition own diagnostics, it means that the malfunctions arising in system of ignition and injection, register in memory of the control unit which can be interrogated, and the deciphered malfunctions will be purposefully eliminated. The capacity block, in comparison with other systems of ignition, is located near the coil 14 of ignition and has for an object to regulate a current of the coil of ignition on control unit signals. The KE-Motronic system has two sensors of a detonation 2, 4 (fig. 6.9) which define a detonation in each separate cylinder and automatically change for them the ignition moment. Additional inductive sensor 3 ( fig. 6.10) the moment of ignition covers a high-voltage wire of 1 fourth cylinder and gives to the control unit at the moment of ignition a signal of ignition which is necessary for the analysis of signals of sensors of a detonation.

The distributor of ignition is established in the block of cylinders on SOHC engines, and on DOHC engines it is established on a back part of a head of the block of cylinders and is put in action by a camshaft the managing director of final valves.

Possible malfunctions of the generator, their reason and ways of elimination