Distributor Operation

EST Distributors With Separate Coil (Typical):

2.8L - Engine Distributor Components:

DELCO REMY DISTRIBUTORS

Distributors with separate coils are used on light duty truck engines. The ignition coil connects to the distributor cap through a high tension wire.
The distributor uses an internal magnetic pickup assembly that consists of a permanent magnet, pole piece with internal teeth, and pickup coil. When the rotating teeth of the timer core line up with the teeth of the pole piece, voltage is induced in the pickup coil. This voltage signals the ignition control module to trigger the primary ignition circuit. Current flow in the primary circuit is interrupted and a high voltage of up to 35,000 volts is induced in the ignition coil secondary winding. This high voltage is directed through the secondary ignition circuit to fire the spark plugs.
The distributor used on the 2.8L engine uses a capacitor for radio noise suppression that is integral with the terminal block.

IDENTIFICATION
The part number (seven digits) is located on a label on the distributor cap.

IGNITION CONTROL MODULE
The ignition control module is a solid state unit containing many complete circuits. The circuits control spark triggering, switching, current limiting, dwell control, and distributor pickup. The vehicle's computer sends signals to the module to control dwell and spark timing. The module may have seven or eight terminals, depending on the ignition system.


POLE PIECE AND COIL ASSEMBLY
The pole piece and plate assembly (often referred to as the pickup coil assembly) located inside the distributor consists of a permanent magnet, a pole piece with internal teeth, and a pick-up coil. When the teeth of the timer core, rotating inside the pole piece, line up with the teeth of the pole piece, an induced voltage in the pick-up coil signals the electronic module to trigger the coil primary circuit. The primary current decreases and a high voltage is induced in the ignition coil secondary winding which is directed through the rotor and secondary leads to fire the spark plugs.

CAPACITOR
The capacitor in the distributor is for radio noise suppression.