1992 Isuzu Stylus RSFACTORY OEM SERVICE PROCEDURE

Idle Air Control Valve

  1. If Idle Air Control (IAC) valve is operating improperly, remove IAC valve from throttle body. Inspect IAC valve and throttle body bore for binding and clogged passages. Repair as necessary. If binding or clogged passages are not present, proceed to next step.
  2. Disconnect electrical connector from IAC valve. Using ohmmeter, check resistance across terminals No. 1 and 2 and across terminals No. 3 and 4. See Fig 1 . Replace IAC valve if resistance is not 40-80 ohms.
  3. Using ohmmeter, check continuity across terminals No. 1 and 4 and across terminals No. 2 and 3. Replace IAC valve if continuity exists.
  4. If IAC valve tests okay, check for faulty connections at IAC valve and ECM. If connections are okay, check input devices used by ECM to control IAC valve operation.
Fig 1: IAC Valve Terminal ID
G90I17994Courtesy of ISUZU MOTOR CO.
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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.

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