Ignition System: Description and Operation

Ignition Timing Control:

A high voltage pulse created in the ignition coil flows through the coil wire to the distributor. The distributor and its rotor will lead the voltage pulse (through rotary motion) to the correct spark plug wire. Through this wire the pulse is led to the spark plug, where it must jump a gap to reach engine ground. When the voltage pulse jumps the gap to ground, it creates a spark (ignition spark) strong enough to ignite the air/fuel mixture in the combustion chamber.


The programmed ignition (PGM-IG) used in this engine provides optimum control of ignition timing by using a microcomputer (ECU) that processes input signals from the TDC/CRANK sensor, throttle angle sensor, coolant temperature sensor and MAP sensor to determine the correct ignition timing at any given driving condition. The ECU sends voltage pulses to the igniter unit to trigger the ignition spark.