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GMC
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1986
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Forward Control 6.2 J, Standard
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Repair and Diagnosis
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Engine Performance
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Tune-Up
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Ignition System - HEI (Federal)
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Overhaul
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Reading Scope Primary Pattern
Reading Scope Primary Pattern
Spark Zone - spark plug arcing.
Coil and Condenser Zone.
Dwell Zone - displays current through coil primary with module activated.