Idle Speed & Mixture

NOTE: Mixture adjustment is not possible on any model.

CAUTION: Some tachometers may not be compatible with ignition system. Consult tachometer manufacturer before connecting tachometer to system. To avoid possible damage to ignitor and/or coil, DO NOT allow tachometer terminal to become grounded.

NOTE: Check and adjust idle speed with air cleaner installed, all air intake system hoses and vacuum lines connected, electronic fuel injection system wiring connectors tight, transmission/transaxle in Neutral, all accessories and electric cooling fan off (if equipped), and engine at normal operating temperature.

Install tachometer on proper terminals of data link connector. See Figure. Start and operate engine at 2500 RPM for about 90 seconds.
Allow engine to idle. Ensure idle speed is within specification. See IDLE SPEED SPECIFICATIONS table. If idle speed is not within specification, check Idle Air Control (IAC) valve, wiring and Electronic Control Module (ECM). See IDLE CONTROL SYSTEM information in SYSTEM/COMPONENT TESTS article. Remove tachometer.

IDLE SPEED SPECIFICATIONS

Application ⁽¹⁾

RPM

Corolla

700

⁽¹⁾	Check with transmission/transaxle in Neutral, parking brake applied and all accessories off.