Ignition System - HEI-Est: Description
The Delco-Remy High Energy Ignition system with Electronic Spark Timing (HEI-EST) is a part of the General Motors Computer Command Control (CCC) systems. The CCC is designed to provide optimum performance through electronic control of air/fuel ratios, spark timing, air management, and idle speed. Some 3.0L, 3.8L, 4.3L, and 5.0L engines also use the Electronic Spark Control (ESC) system to retard spark timing when detonation occurs.
The distributor contains a HEI-EST control module and magnetic pick-up assembly. The pick-up assembly consists of a permanent magnet, a pole piece with internal teeth, and a pick-up coil. There are no vacuum or centrifugal advance mechanisms.
Distributors may be equipped with either an integral or externally mounted ignition coil. Some distributors with externally mounted ignition coils may be equipped with sealed module connectors. See Figure.