2. The ignition system is powered by low voltage battery power to the ignition coil where it is converted to high voltage. The high voltage has enough power to create a spark between the spark plug electrodes at high compression. Low voltage circuit (or primary) consists of wiring from the battery to the ignition switch, wiring from the ignition switch to the primary coil and power terminal on the electronic module, wiring from the primary winding of the coil to the control terminal on the electronic module. High voltage circuit (or secondary) consists of a high-voltage winding of the ignition coil, high-voltage wiring from the ignition coil to the cover of the breaker-distributor to the distributor slider, to the spark plugs and spark plugs.
3. The system functions in the following way. The current flowing through the low voltage winding of the ignition coil generates a magnetic field around the secondary winding. When the engine rotates, the sensor generates an electrical impulse, which is amplified in the electronic module and used to turn off the low voltage circuit.
4. The drop in magnetic field strength in the secondary winding generates a high voltage, which is then applied to the corresponding spark plug through the breaker-distributor cover and the distributor runner. The low voltage circuit is automatically switched on again by the electronic module, the magnetic field starts to rise again and the cycle is repeated for the next spark plug. Ignition timing is automatically adjusted to provide precise spark timing based on engine speed and load.
HEI system
5. It includes a distributor with a chopper, an electronic switching/amplification module, an ignition coil and spark plugs.
6. The electrical impulse required to turn off the low voltage circuit is generated by a magnetic trigger in the distributor. The trigger wheel rotates in a constant magnetic field. The magnitude of the magnetic field between two poles (between the protrusions of the stator and the gear) depends on the air gap between the two poles. When the air gap is at its minimum, the gear lobe is directly in front of the stator lobe, this is the moment of momentum. As the magnetic field between the stator lugs and the gear changes, a voltage is generated in the trigger winding installed below the gear. This voltage is then amplified by the electronic module and used to turn off the low voltage circuit. Each cylinder has one trigger and stator protrusion.
7. Ignition advance is a function of the distributor, and is regulated mechanically and by vacuum. The mechanism of the mechanical regulator consists of two weights, which, when the engine speed increases, diverge from the distributor shaft under the action of centrifugal force. Diverging from each other, the weights rotate the gear wheel relative to the distributor shaft and thus correct the moment of ignition spark formation. The weights are held in position by two weak springs, and the tension of these springs is largely dependent on the correct operation of the ignition advance system.
8. The vacuum regulator consists of a diaphragm, one side of which is connected by a hose to a small hole in the carburetor, and the other side is connected to a distributor. The vacuum in the intake manifold and carburetor, which varies with engine speed and throttle position, causes the diaphragm to move, which in turn moves the base plate and corrects the ignition timing. The correct operation of the system depends largely on the stiffness of the spring in the diaphragm assembly.
MSTS-i system
9. This system has a distributor with "hall effect" (or speed/crankshaft position sensor on X16 SZ model), intake manifold pressure sensor, oil temperature sensor, module, ignition coil and spark plugs.
10. On 1.6 liter models, an electrical impulse to turn off the low voltage circuit is generated by a sensor in the distributor. The trigger blade rotates in the gap between the permanent magnet and the sensor. The trigger blade has four slots, one for each cylinder. When one of the slots aligns with the sensor, the magnetic field can pass between the magnet and the sensor. The sensor senses changes in magnetic flux and sends a pulse to the MSTS-i module, which turns off the low voltage circuit.
11. On 1.8 liter models, an electrical impulse to turn off the low voltage circuit is generated by a speed / crankshaft position sensor, which is activated by a special gear on the crankshaft. The gear wheel has 35 equally spaced teeth, with the 36th tooth missing. This missing tooth is used by the sensor to determine the position of the crankshaft relative to TDC (top dead center) piston number 1.
12. Information about the load on the engine is supplied to the MSTS-i module from the pressure sensor, which is connected to the carburetor by a vacuum tube. Additional information comes from the oil temperature sensor. The module selects the optimal ignition timing based on the information received from the sensors. The amount of advance can thus be constantly changed, depending on the mode of operation of the engine.
Multec system with MSTS-i
13. The ignition system is fully electronic and there is an electronic control device (ECU), installed in the driver's footwell. Includes: Distributor (driven from the left end of the camshaft and containing an amplifier module) along with fuel octane coding plug, spark plugs, high voltage wires, ignition coil secondary and electrical wiring.
14. The ECU controls the ignition system and the fuel injection system, and is essentially the engine management system. For more information not covered here, see Sections 4B and 4C.
15. For the ignition system, the ECU receives information in the form of electrical impulses or signals from the distributor (about engine speed and crankshaft position), from coolant temperature sensor (about engine temperature) and from the manifold pressure sensor (about engine load). In addition, the ECU receives information about the octane number of the fuel used from the coding plug (for adjusting the ignition timing to the type of fuel used) and from the automatic transmission control unit (to soften gear changes by reducing the ignition timing ignition when shifting).
16. All these signals are compared by the ECU with the set values programmed into memory. Based on this information, the ECU selects the ignition timing corresponding to these values, l controls the high-voltage winding of the ignition coil through the amplifier module.
17. The system is so sensitive that at idle speed, the ignition timing can constantly change; this must be remembered when checking the ignition timing.
18. The system installed on the C18 NZ model is similar to that described above, except that the amplifier module is made as a separate unit. The ECU detects engine speed and crankshaft position using a sensor mounted on the right front end of the engine block. It is recorded by a 58-tooth disk mounted on the crankshaft so that the gap formed by the two missing teeth is the reference point indicating the ECU at TDC.
19. Please note that this simplifies the function of the distributor, which should simply give a voltage pulse to the corresponding spark plug; and no further correction of the ignition timing is required
DIS system
20. On all X16 SZ engines, and on C20 XE engines (with two overhead cams) since 1993, the DIS module has been used in place of the distributor and ignition coil. On the X16 SZ engine, the DIS module is attached to the camshaft housing at the location normally occupied by the distributor. On the C20 XE engine, a camshaft position sensor is attached to the cylinder head, located at the end of the exhaust camshaft, in the position normally occupied by the distributor. The DIS module is bracketed to the cylinder head at the end of the intake camshaft.
21. The DIS module consists of two ignition coils and a control unit located in the housing. Each ignition coil supplies high voltage to two spark plugs. One ignition spark is generated in the piston cylinder on the compression stroke and one spark is generated in the piston cylinder on the exhaust stroke. This means that one cylinder during each ignition cycle is supplied with "excess ignition spark", but it has no harmful effect. This system has the advantage that there are no moving parts (so there is no wear), and the system is largely unattended.
Motronic M4.1 and M1.5 systems
22. This system controls both ignition and fuel injection.
23. The Motronic module receives information from the speed/crankshaft position sensor, from the coolant temperature sensor located in the thermostat housing, from the throttle position sensor, from the airflow meter and, on models with a catalytic converter, from the oxygen sensor located in the exhaust system (Section 4C).
24. Output signals from the module control the fuel priming pump, fuel injectors, idle speed, and the ignition circuit. Based on the input signals from various sensors, the module calculates the optimal ignition timing and fuel injector open duration suitable for various engine modes. This system provides very precise engine control in all modes, improving fuel consumption and overall vehicle handling characteristics, and reducing the amount of harmful substances in the exhaust gases.
25. In more detail, the components of the fuel injection system are described in Section 4B.
Motronic M2.5 and M2.8 systems
26. The system is similar to that described for single overhead cam models, with the following differences.
27. Along with the speed/crankshaft position sensor, a distributor with "hall effect" (similar to that described in this Chapter for MSTS-i system).
28. The system also has a separate ignition booster module that transmits amplified signals from the main system module to induce a high voltage pulse in the ignition coil. The module is mounted on the ignition coil bracket/base plate.
29. Additionally, the Motronic module receives information from a knock sensor mounted on the cylinder block, which is sensitive to knock (or pre-ignition), allowing the module to advance the ignition timing, thus preventing engine damage.
Simtec 56.1 system
30. This system uses a large number of electronic components instead of mechanical parts such as sensors and actuators. They provide the system with more accurate data, on the basis of which it is possible to more accurately control the operating modes of the engine.
31. The control unit is equipped with an electronic ignition control system, called a microprocessor ignition system, with inductive control, (or MSTS-i), And a node such as a mechanical high voltage distributor is no longer required. The block is located behind the trim panel, on the right side in the footwell (in the door pillar).
32. The ignition coil has been replaced by a dual coil, which is switched by signals from the control unit.
33. The sensor on the camshaft indicates critical positions when the inductive pulse sensor on the crankshaft is triggered. These positions are called TDC ("Top dead center"), crankshaft angle and engine speed. The signals are used by the control unit to calculate the ignition timing and fuel injection timing.
34. An air flow mass tape meter measures the mass of air entering the engine. The system uses this information to calculate the correct amount of fuel to inject into the engine.
35. Inlet air temperature sensor (NTC), is installed in the air intake duct between the air filter and the air flow meter.
36. The system activates the carbon filter valve. Tank ventilation controlled by lambda control (or oxygen sensor) and corrected by the computer in the control unit.
37. There is also a detonation control system. It eliminates the need for octane adjustment, as this is done automatically by the control unit.
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