Minimum Idle Speed Check
- Idle stop screw is preset at factory and normally does not require adjustment. To check setting, remove air filter ducting as necessary and plug any open vacuum ports. If idle stop screw plug is in place, use a sharp awl to puncture plug and pry it out. Connect a tachometer or Scan tester. See Fig 1 .
- Ensure IAC valve is connected and ground ALDL diagnostic connector. See Figure . Turn ignition on, but do not start engine. Wait 45 seconds while IAC valve pintle extends and seats in throttle body.
- With key on, engine off, and ALDL still grounded, disconnect the IAC valve electrical connector. Remove ALDL ground and start engine. With transmission in Neutral, allow engine RPM to stabilize.
- Check idle RPM on tachometer or Scan tester. If idle speed is not to specification, adjust idle stop screw. See MINIMUM IDLE SPEED SPECIFICATIONS table in this article. Turn ignition off. Reconnect IAC valve. Seal stop screw with silicone sealant. Refit components.
MINIMUM IDLE SPEED SPECIFICATIONS
| Application | RPM | |
|---|---|---|
| 1.6L | ||
| Automatic Transaxle (Neutral) | 450-550 | |
| Manual Transaxle | 550-650 | |
| 2.0L | 550-650 | |