Distributor: Description and Operation

Distributor:

The distributor acts as a rotary switch, distributing the firing voltage using a distributor rotor and distributor cap. The distributor cap and rotor deliver high voltage to the spark plugs in a pre-set sequence. The distributor is driven by the camshaft and is located on the right side of the engine. The pick-up coil is located inside the distributor and utilizes an external igniter bolted to the side of the distributor.
As the reluctor rotates inside the distributor it produces a voltage pulse in the pick-up coil. The voltage pulse is transmitted to the power transistor which interrupts current flow in the primary circuit. The interruption induces high voltage in the secondary coil and fires a spark plug.
The TDC/CYL sensor, found inside the distributor housing, consists of the TDC sensor rotor, CYL sensor rotor, their associated pick-up coils, and a common shaft that is directly coupled to the camshaft. As the teeth on the sensors break the flux lines of their respective pick-up coils a voltage pulse is generated. These pulses are the input signal to the engine control unit (ECU).
The TDC sensor references #1 cylinder at TDC for the sequential fuel injection. The TDC sensor also supplies the ECU with an engine RPM signal.
The CYL sensor supplies the ECU with information needed to determine fuel injection timing for each cylinder.