Step "A"
- Check for DTCs. Ensure timing is correct, spark plugs and air cleaner are okay, and PCV system is operating properly. See SELF-DIAGNOSTICS - INTRODUCTION article. Connect tachometer.
- Set parking brake. Start engine and run at 3000 RPM with no electrical loads (headlights, blower motor, rear defogger, A/C and cooling fan off) and transmission in Park or Neutral. When radiator cooling fan comes on, allow engine to idle. Disconnect IAC valve 2-pin connector. If engine stalls, depress accelerator pedal slightly and start engine. Stabilize engine speed at 1000 RPM and slowly release accelerator pedal.
- Check idle speed with no electrical loads. See IDLE SPEED SPECIFICATIONS (PRELUDE) table. If idle speed is as specified, go to Step "B" . If idle speed is not as specified, remove idle adjusting screw cap located on top of throttle body. See Figure. Turn idle adjusting screw, until idle speed is as specified.