Deceleration Control Valve

1989 GMC Magnavan 5.7 K, 3L80/M40SECTION Deceleration Control Valve

To assist in preventing backfiring during high vacuum conditions, a deceleration valve is used. High vacuum draws valve diaphragm down and opens valve to allow air from air cleaner to flow into intake manifold. This process leans the mixture created by high vacuum.

CAUTION: If steam cleaning components or using high pressure detergent, mask intake air cleaner and air pump completely.
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.