How a Battery Functions

Idle Speed Inspection Overview

With a PGM-FI (Programmed Fuel Injection) engine, the idle speed is adjusted using the idle adjusting screw, which is located on the throttle body. The setting of the idle adjusting screw determines the rate at which air flows through the bypass passage.

You should remember that the idle speed is also controlled by other one or two valves Rotary Air Control Valve (RACV, or EACV and fast idle thermo valve combination).

The RACV (Rotary Air Control Valve) is not fitted to the vehicles with electronic throttle control system (ETCS). On such vehicles, idle air control is performed by the electronically controlled throttle valve.

On engine with EACV, if you try to adjust the idle speed by turning the adjusting screw, the EACV will operate to compensate your adjustment and no change will occur. Therefore, it is required to disconnect the EACV (Electronic Air Control Valve) connector to deactivate the EACV during adjustment.

On engine with RACV, it is not necessary to disconnect the RACV connector. However, use of a scan tool is recommended for more accurate adjustment.

 CAUTION:

• Before starting the engine, apply the parking brake and make sure the transmission is in the neutral or parking position.
• When the engine is running, be careful not to touch its moving parts.
• Make sure the workshop is well ventilated when working with the engine running.

Idling Inspection

•  Leave the idle air control (IAC) valve connected (K20A6 engine)
•  Before checking the idle speed, check these items;

• • The malfunction indicator lamp (MIL) has not been reported on.
• • Ignition timing
• • Spark plugs
• • Air cleaner
• • PCV system

• • Connect the scan tool on the data link connector (DLC) located under driver's side of the dashboard.

NOTE:

If the idle speed is not within specification, do the ECM/PCM idle learn procedure. If the idle is still out of specification, go to the Symptom Troubleshooting Index.

ECM/PCM Idle Learn Procedure

Do the idle learn procedure whenever you do any of these actions;

• The ECM/PCM is replaced
• The ECM/PCM is reset
• The throttle body is replaced
• The throttle body is cleared