Distributor: Description and Operation

Distributor Assembly:

PURPOSE
The distributor houses the Camshaft Position (CMP) Sensor, and distributes high voltage secondary output through the rotor and distributor cap and spark plug wires to the spark plugs.

OPERATION
The distributor uses the hall effect device called the CMP Sensor to generate a sync signal. This sensor detects the shutter on the distributor shaft. Its signal is used in conjunction with the Crankshaft Position (CKP) to differentiate between fuel injection and spark events. It is also used to synchronize the fuel injectors with their respective cylinders.

The CMP Sensor consists of a rotating pulse ring (shutter) mounted to the distributor shaft. It is included as part of the distributor switch plate. The CMP Sensor is a Hall Effect switch. The pulse ring rotates 180 degrees through the sync signal generator.

When the leading edge of the pulse ring enters the sensor, the following occurs: The interruption of magnetic field causes the voltage to switch high resulting in a sync signal of 5 volts.

When the trailing edge of the pulse ring leaves the sensor, the following occurs: The change of the magnetic field causes the sync signal voltage to switch low to 0 volts.