Tune-Up Procedures - V6: Distributor

All models are equipped with High Energy Ignition (HEI) system and no adjustment is required.

NOTE: Turbocharged engines use a modified HEI system which is called Electronic Spark Control (ESC). The ESC system is used to control engine detonation by automatically retarding ignition timing (up to 20°) during periods of engine operation when detonation occurs.

Fig 1: 1975-79 196" & 231" (Except VIN 2) Firing Order & Timing Marks

Courtesy of GENERAL MOTORS COMPANY

Fig 2: 1979 231" (VIN 2) Firing Order & Timing Marks

Courtesy of GENERAL MOTORS COMPANY