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Mechanical Inspection: Compression

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

CAUTION: Use a remote starter to crank engine during compression test. DO NOT  use the ignition switch. Fuel injectors on many fuel- injected models are triggered by computer when ignition switch is in cranking mode. The excess fuel can cause flooding, crankcase contamination or hydrostatic lock.