Electronic Ignition System 1.8L

The electronic ignition system consists of a distributor, spark plugs, ignition coil, power transistor, Electronic Control Unit (ECU), high tension cables, and wiring. The distributor incorporates power transistor, ignition coil and crank angle sensor. The ECU functions to detect engine operating conditions from various sensor signals and based on these signals, regulates ignition timing.

When ignition is turned on, battery voltage is applied to ignition coil primary winding. As distributor shaft rotates, ignition signals are transmitted from the ECU to power transistor. These signals activate power transistor to cause ignition coil primary winding current to flow from ignition coil negative terminal through power transistor to ground or be interrupted, repeatedly. This action induces high voltage in the secondary winding of ignition coil. From the coil, the secondary winding current flows through the distributor and spark plug to ground, thus causing ignition in each cylinder.