Fig. 5.1. Ignition system circuit diagram
B - Battery
RP - Distributor
S - Ignition switch
SE - Ignition Control Unit
SV - Shielded wire
ZC - Ignition Coil
The ignition system is fully electronic, inductive type, includes a distributor without a breaker (camshaft driven), ignition control module, spark plugs, spark plug wires, spark plug coil and wiring harness.
The system is divided into two circuits: primary (low voltage) and secondary (high voltage). The primary circuit includes: battery, ignition switch, primary windings of the ignition coil, ignition control unit, distributor pulsator winding and electrical wiring. The secondary circuit includes: secondary windings of the ignition coil, distributor rotor, spark plugs and high-tension wires.
The distributor has devices that change the ignition timing in response to changes in engine speed and load. This is achieved by centrifugal units (spring loaded weights increase the lead as engine speed increases) and vacuum (the diaphragm block attached to the distributor body increases the advance as the vacuum increases) corrections.
The pulsator winding in the distributor produces a weak magnetic field when the ignition is on. As the engine rotates, the poles of the pulsator pass through the magnetic field and a signal is sent to the ignition control unit, where it is used to switch the higher voltage and current required to operate the ignition coil.
High voltage for the spark plugs is produced in the ignition coil when the current in the primary winding is suddenly interrupted by the control unit. High voltage passes through the high voltage wire to the distributor rotor, where it is fed to the corresponding contact in the distributor cap, and through the wire to the spark plug. Finally, high voltage jumps across the spark plug gap and produces the spark needed to ignite the fuel-air mixture in the cylinder.
Warning: The voltages produced by the contactless ignition system are significantly higher than those produced by conventional systems (with contact breaker). Use extreme caution when working on the system with the ignition on. People with surgically implanted cardiac pacemakers should refrain from working on ignition system components or with diagnostic equipment.