Distributor: Description and Operation

PURPOSE
The distributor is a multi-function assembly.
- It provides the engine control module (ECM) with input signals related to engine speed and crankshaft angle.
- Directs high voltage ignition coil output to the spark plugs in proper sequence (firing order).

OPERATION
The integral camshaft position sensor sends the ECM signals representing engine speed and crankshaft angle. The ECM controls ignition timing by regulating the ground circuit for the internally mounted ignition control module (in distributor). The ignition control module switches the primary circuit of the internally mounted ignition coil. The ignition coil sends secondary voltage to the ignition rotor where it gets distributed to the proper cylinder via the distributor cap and ignition cables (high-tension leads).

To accomplish this, the rotor is mounted on the driven shaft and acts as a rotary contact, directing ignition coil voltage to each spark plug terminal as it turns inside the distributor cap.
The distributor is camshaft-driven and turns at half crankshaft speed.

CONSTRUCTION
The distributor assembly houses several components of the ignition system, some of which are not serviceable separately from the assembly itself.

View: System Relational Diagram:

The integral components are as follows:
- Ignition coil
- Ignition control module
- Camshaft position sensor

View: Distributor And Related Components:

Removable components:
- Distributor cap (1)
- Ignition rotor (2)
- Cover (3)
- Packing (4)
- Distributor (5)