Tune-Up - 6 CYL: Distributor

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

NOTE: Turbocharged engines use a modified H.E.I, system which is called Electronic Spark Control (ESC). The ESC system is used to control engine detonation by automatically retarding ignition timing (up to 18° to 20°) during periods of engine operation when detonation occurs.

Fig 1: 173" Firing Order and Timing Marks

Courtesy of GENERAL MOTORS COMPANY

Fig 2: 231" and 252" Firing Order and Timing Marks

Courtesy of GENERAL MOTORS COMPANY