Incorrect Idle At Engine Start-Up

WARNING: This page is about a different car, the 1994 Toyota 4Runner. However, it is still accessible from the selected car via links, so may be relevant.

Check for defective throttle linkage or cable.
Check throttle opener or dashpot (if equipped).
Check idle-up vacuum switching valve (if equipped) and wiring.
Check idle air control valve (if equipped) and wiring.
Check coolant temperature sensor and wiring.
Check Electronic Control Module (ECM) and wiring.