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Home >> GMC >> 1989 >> Forward Control 4.8 T, Standard >> Repair and Diagnosis >> Engine Performance >> Ignition System - HEI/Est/ESC >> Description >> HEI-Est With Electronic Spark Control (ESC)

HEI-Est With Electronic Spark Control (ESC)

Electronic Spark Control (ESC) adds detonation detection and correction functionality to the HEI-EST system. This allows maximum performance due to aggressive spark advance schedules.

No modifications are made to the distributor or ignition module. Rather, a detonation sensor or detonation sensor/detonation module combination is wired to the ECM and is treated like another sensor. When the ECM detects detonation, timing is retarded accordingly.