Distributor: Description and Operation

Distributor Assembly:

PURPOSE
Distributes secondary spark to the correct cylinder.

OPERATION
The distributor is mounted on the rear face of the cylinder head and is driven off the end of the camshaft. Ignition advance is controlled two ways:

Mechanically
^ According to engine speed by weights inside the distributor body.
^ According to engine load by vacuum control.

Electronically
^ According to altitude by the ignition module via the Barometric Pressure Sensor input to the Powertrain Control Module (PCM).

When the distributor shaft rotates, the magnetic pulse is generated in the pickup coil. The pickup coil is part of the electronic ignition module, which controls the current through the ignition coil primary winding. As the coil windings collapse, the field induces a high voltage pulse in the secondary windings. The ignition coil transfers the secondary voltage to the distributor rotor. The distributor rotor transfers the voltage to each spark plug wire.