1987 Jaguar XJ12 distributer and rotor

DESCRIPTION
The Lucas Constant Energy Ignition system includes a breaker-less distributor, amplifier module, an ignition coil, ignition switch, and battery. See WIRING DIAGRAMS . No ballast resistor is required.
The distributor has conventional centrifugal and vacuum advance systems, an anti-flash shield, rotor, reluctor, and pick-up coil. See Fig. 5 . The reluctor is a gear-shaped component with 6 or 12 teeth, one for each cylinder.
The pick-up coil includes a winding, pole piece and a permanent magnet. A 2-wire shielded harness connects it directly to the amplifier module. The amplifier module, housed in an aluminum case, is located near the distributor.
OPERATION
Reluctor turns with distributor shaft. As each of the 6 or 12 teeth pass across the pick-up coil's pole piece, the magnetic field strength around the pick-up winding is intensified. This creates a voltage in pick-up coil windings.
The rise and fall of this voltage is sensed by the amplifier module, which then sends a signal cutting off voltage to the primary circuit of ignition coil. This causes a voltage surge in the secondary, firing spark plugs.
ADJUSTMENTS
PICK-UP COIL-TO-RELUCTOR AIR GAP
Air gap should not need resetting unless it has been tampered with. Always use a plastic feeler gauge when checking or setting air gap. See Fig. 1 . Gap must be checked at each reluctor tooth.
To check air gap, align reluctor tooth with pole piece of pick-up coil. Insert plastic feeler gauge. On XJ6 III, set air gap at .008-.014" (.20-.35 mm).
To adjust air gap, loosen pick-up coil mounting screws. Align reluctor tooth with pole piece of pick-up coil. Insert feeler gauge and move pick-up coil against gauge. Tighten mounting screws.