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Home >> GMC >> 1995 >> Forward Control 7.4 N >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 9 (Engine Controls - Basic Testing - 5.7L) >> Preliminary Inspection & Adjustments >> Mechanical Inspection >> Compression
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Mechanical Inspection: Compression

WARNING: This page is about a different variant/trim than selected.

Check engine mechanical condition using a compression gauge, vacuum gauge or engine analyzer capable of performing a relative compression test. If using engine analyzer, see engine analyzer instruction manual for availability and description of relative compression feature.

WARNING: Because fuel injectors on many models are triggered by ignition switch during cranking mode, DO NOT  use ignition switch during compression tests. Use a remote starter to crank engine to prevent fire hazard or engine's oiling system contamination.