IAC - Idle Air Control

1987 Chevrolet R 30 P/U 2WD V8-350 5.7LSECTION IAC - Idle Air Control

The IAC is controlled by the ECM to maintain specified idle speed. The ECM controls the IAC with voltage pulses (counts) and these counts are displayed in this position. The number of counts displayed represents the position the ECM "thinks" the IAC is in. Normal readings are in the 5-50 range.

RENDER: 1.0x

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When to See a Mechanic

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

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