Idle Speed & Mixture

NOTE: Mixture adjustment is not possible.

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, ignition timing properly set, electric cooling fan off (if equipped), A/C and all accessories off and engine at normal operating temperature.

Warm engine to normal operating temperature. Shut engine off. Connect scan tester to data link connector No. 3. See Figure. Scan tester is used to read engine RPM.
Apply parking brake. Place transmission/transaxle in Neutral. Start engine and maintain engine at 2500 RPM for 90 seconds and then allow engine to idle.
Ensure idle speed is within specification. See the 4-CYLINDER 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 in the SYSTEM/COMPONENT TESTS article. Remove scan tester.

4-CYLINDER IDLE SPEED SPECIFICATIONS

Application ⁽¹⁾

RPM

Tercel

700-800

⁽¹⁾	Check with engine at normal operating temperature, transmission/transaxle in Neutral, parking brake applied, ignition timing properly set, electric cooling fan off (if equipped), and A/C and all accessories off.