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6. System of ignition

Sensor distributor of ignition 3810.3706

1 – roller;
2 – ignition sensor distributor case;
3 – latch;
4 – contactless sensor;
5 – case of the vacuum regulator;
6 – diaphragm;
7 – draft of the vacuum regulator;
8 – basic plate of the centrifugal regulator;
9 – ignition distributor rotor;
10 – side electrode;

11 – cover;
12 – central electrode;
13 – piece of coal of the central electrode;
14 – resistor;
15 – external contact of a rotor;
16 – leading plate of the centrifugal regulator;
17 – small weight of the centrifugal regulator;
18 – basic plate of the contactless sensor;
19 – screen.

The scheme of check of the contactless sensor on the car

1 – ignition sensor distributor;
2 – the voltmeter having a scale limit not less than 15 V and internal resistance not less than 100 kOhm;

3 – view of the plug socket of the sensor distributor of ignition.

Scheme of contactless system of ignition

1 – ignition switch;
2 – ignition relay;
3 – switchboard;

4 – ignition coil;
5 – ignition sensor distributor;
6 – spark plugs.

System of ignition – contactless. Consists of the sensor distributor, the switchboard, the coil of ignition, candles, the switch of ignition and wires of high and low voltage. A small part of cars with the engine of 1600 cm 3 was equipped with a microprocessor control system of the engine which is not described here.

The sensor distributor of ignition 3810.3706 — four-spark, with the contactless sensor of the operating impulses both the ignition advancing regulators which are built in vacuum and centrifugal. The initial corner of an advancing of ignition with a frequency of rotation of a bent shaft of 750-800 min. –1 has to make 1±1 ° to VMT.

The sensor distributor performs two main functions: first, sets the sparking moment depending on its initial installation, speed of a bent shaft and load of the engine, and secondly, distributes impulses of high voltage ("spark") on cylinders according to order of their work — the rotor (runner) for this purpose serves. Not to be mistaken at assembly, the runner is installed on a basic plate of the centrifugal regulator only in one situation. In the runner there is a pomekhopodavitelny resistor with a resistance of 1 kOhm.

Operation of the contactless sensor is based on Hall's effect. At the included ignition on the sensor supply voltage moves. At rotation of the roller of the sensor distributor through a gap of the sensor there passes the steel screen with rectangular cuts. While in a gap there is a screen plate, from the operating conclusion of the sensor stress as soon as in a gap there is a cut is removed, tension on the operating conclusion sharply falls. Thus, the beskontakny sensor for each turn of the roller of the sensor distributor gives four rectangular impulses (on number of cuts in the screen) that corresponds to the ignition moment in each of engine cylinders.

It is possible to check operability of the contactless sensor, having collected the scheme shown in the drawing. Slowly rotating the ignition sensor distributor roller, we monitor indications of the voltmeter. Tension has to change sharply from minimum (no more than 0,4 In) to maximum (no more, than supply voltages are 3 V less). The faulty sensor is not subject to repair (except for wire breakage between the sensor and a block on the sensor distributor case). If the steel screen with cuts touches the sensor (is determined by easy jamming or the scratching sound at rotation of the roller, and also visually, after partial dismantling of the sensor distributor), check an axial side play of the roller and landing of the screen. If necessary replace the sensor distributor.

The centrifugal regulator increases an ignition advancing corner with growth of speed of the engine, entering work at 900–1400 min. –1. At rotation of the roller of the sensor distributor regulator small weights under the influence of centrifugal forces disperse, overcoming resistance of springs, and shift a basic plate of the centrifugal regulator clockwise concerning the roller. For optimum operation of the regulator of a spring have different rigidity. More rigid (thick) spring enters work later, approximately on the middle of a full speed of a plate — therefore it is put on a rack with a gap whereas softer (thin) spring is always tense. The maximum movement of a basic plate is limited to a cut in it and makes about 12 ° on the distributor that about 24 correspond to an ignition advancing corner ° on a bent shaft.

At survey of the centrifugal regulator be convinced that small weights freely move on axes, their damping plastic ringlets are not lost, the thin spring is tense, and the basic plate comes back under the influence of springs to a starting position. If necessary grease the sensor distributor roller with several drops of engine oil.

The vacuum regulator increases an ignition advancing corner depending on load of the engine. It consists of the vacuum chamber with the steel sprung membrane which is connected by draft to a basic plate of the contactless sensor. Under the influence of depression the membrane caves in, overcoming spring resistance, and turns a basic plate counterclockwise. The maximum movement is limited to a cut on draft and makes about 9 ° on the distributor (18 ° on a bent shaft).

Depression for operation of the vacuum regulator is selected from an opening in the mixing camera of the carburetor opposite to a butterfly valve of the first camera. At partial opening of the gate (underload) depression behind it is big, and the regulator as much as possible shifts the sparking moment towards an advancing. At full opening of the gate (full loading) depression behind it falls, and the regulator returns a basic plate of the contactless sensor in a starting position.

Roughly it is possible to estimate serviceability of the vacuum regulator directly on the car. On the working engine we disconnect the vacuum hose conducting to the regulator from the carburetor union. If now to create depression in a hose (it is possible a mouth), turns of the engine have to increase, and at depression removal – again to decrease. Depression has to remain at least several seconds if to press a hose. Visually it is possible to be convinced of operability of the vacuum regulator, having partially disassembled the sensor distributor (see Dismantling of the sensor distributor of ignition) and giving depression to the inlet union of the regulator. At the same time the screen of the sensor distributor has to turn on a corner 9±1 °, and at depression removal – without jamming to come back.

Exact check and setup of vacuum and centrifugal regulators of an advancing of ignition are made at special stands. In house conditions it is not recommended to be done. At failure of the vacuum regulator it should be replaced, at malfunction of centrifugal – to replace the sensor distributor.

The switchboard — type 3620.3734, either HIM-52, or BAT10.2, or 76.3734, or RT1903, or PZE4022 — disconnects a power-supply circuit of primary winding of the coil of ignition, transforming the operating sensor impulses to current impulses in the ignition coil. The switchboard is checked by an oscillograph by a special technique and is not maintainable; at suspicion it is recommended to replace it with malfunction. It is forbidden to disconnect the switchboard socket at the included ignition – it can cause its damage (as well as other components of system of ignition).

The ignition coil — type 27.3705 or 27.3705-01, either 8352.12, or ATE1721 — oil-filled, with the opened magnetic conductor. Data for check: resistance of primary winding at 25 °C – (0,45±0,05) Ohms, a secondary winding – (5,0±0,5) kOhm. Isolation resistance on weight – not less than 50 megohms.

Spark plugs – the A17DVR or A17DVRM type, either A17DVRM1, or their import analogs (with pomekhopodavitelny resistors with a resistance of 4-10 kOhm). A gap between electrodes – 0,7–0,8 mm.

High-voltage wires – with the distributed resistance (2550±270) Ohms/m. It is forbidden to touch high-voltage wires on the working engine – it can lead to an electric trauma. It is also forbidden to launch the engine or to allow it to work with the broken-off high-voltage chain (the removed wires or a cover of the sensor distributor) – it can lead to a progar of isolation and failure of electronic components of system of ignition. As the exception is allowed short-term check of system of ignition "on a spark", at the same time the contact of the checked high-voltage wire has to be reliably fixed at distance of 8-10 mm from "mass" of the car. It is forbidden to hold a wire hands or the tool (even with the isolated handles).

The ignition switch – type 2101-3704000-11, with the anti-theft locking device. At turn of a key tension comes to situation "ignition" on the operating entrance of the additional relay which, in turn, gives tension on the coil of ignition and the switchboard.