Engine Compression

1987 Chevrolet Astro Van Cargo, 4.3 Z, StandardSECTION Engine Compression

When making compression checks, disconnect ignition switch connector (Pink wire) from High Energy Ignition (HEI) system. With air cleaner removed, throttle wide open, and all spark plugs removed, crank engine through at least 4 compression strokes.

COMPRESSION SPECIFICATIONS

Application Specification
Compression Ratio 8.3:1
Compression Pressure 140 psi (10 kg/cm2 )
Minimum Pressure 100 psi (7 kg/cm2 )
Maximum Variation 30 psi (2 kg/cm2 )
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.