With EEC II & III

Distributor exploded view:

Bi-level rotor & distributor cap:

Distributor Cap:

Operation
The EEC system uses a Dura Spark III ignition module and coil to generate the required high voltage spark. Distribution of secondary voltage to the spark plugs is accomplished with a unique distributor used exclusively on the EEC systems, Fig. 1. All ignition timing is controlled by the ECA. There are no mechanical or vacuum advance mechanisms used with this distributor.

Construction
Since this system is capable of firing a spark plug at any point within a 50° range depending on calibration, the increased spark capability requires greater separation of adjacent distributor cap electrodes to prevent cross fire. The distributor cap and rotor are of a special two level design, Fig. 2, made to accommodate the additional advance capability of this system.

Both the rotor and cap have upper and lower electrode levels. As the rotor turns, one of the high voltage electrode pickup arms aligns with one spoke of the distributor cap center electrode plate, allowing high voltage to pass from the plate through the rotor to the terminal on the distributor cap and out to the spark plug.

NOTE: The distributor assembly and rotor shown in Figs. 1 and 2 are of the early 1979 design and are identical to the units used on 1978 and early 1979 Versailles with the EEC I system. A late 1979 (second generation) distributor is being used as a running change for all EEC II systems. The early and late 1979 designs are interchangeable as complete distributor assemblies only. However, sub-assemblies for the two distributors are not interchangeable. Refer to "EEC I,II & III Distributor Service" for information on how to differentiate between the early and late type.

The numbers, Fig. 3. molded into the top of the cap are wire identification numbers. Due to the unique design of the distributor cap and rotor, the wires are not arranged in the cap in the firing order. The inner ring of numbers is for the Versailles with V8-3O2 which uses the EEC I system. The outer ring of numbers is for use in the EEC II system.