See Figure 1
Electronic ignition systems offer many advances over the conventional breaker point ignition system. By eliminating the points, maintenance requirements are greatly reduced. An electronic ignition system is capable of producing much higher voltage, which in turn aids in starting, reduces spark fouling and provides better emission control.
This book contains simple testing procedures for your Tercel electronic ignition system.
The electronic ignition system consists of a distributor with a signal generator, an ignition coil and an electronic igniter. The signal generator is used to activate the electronic components of the ignition. It is located in the distributor and consists of three main components; the signal rotor, the pick-up coil and the permanent magnet. The signal rotor (not to be confused with the normal rotor) revolves with the distributor shaft, while the pickup coil and the permanent magnet are stationary. As the signal rotor spins, the teeth on it pass a projection leading from the pickup coil. As they pass, voltage is allowed to flow through the system, firing the spark plugs. There is no physical contact and no electrical arcing, hence no need to replace burnt or worn parts.
Service consists of inspection of the distributor cap, rotor and the ignition wires, replacing them as necessary. In addition, the air gap between the signal rotor and the projection on the pickup coil should be checked periodically.