NIPPONDENSO Electronic Ignition System: Description
The Nippondenso electronic ignition system includes a breakerless distributor, an ignitor (ignition control unit), a special ignition coil, and ignition switch.
The distributor consists of a housing, rotor, and cap. It contains a signal rotor (timing rotor or reluctor), magnet, and a magnetic pick-up coil assembly. See Fig 1. On Subaru models, the ignitor is mounted inside the distributor.
On other models, the transistorized ignitor is mounted on the ignition coil housing. Distributors contain both centrifugal and vacuum advance mechanisms.
Toyota distributor is shown. Subaru distributors contain an integral ignitor.