An engine idle speed control device set a target idle speed NsetN for a
non-traveling range is set to a high value to activate the catalytic
converter early, after the engine is started. Upon detecting that the
automatic transmission has been shifted from a non-traveling range to a
traveling range, the target idle speed is lowered to a first traveling
idle speed Nset1. A feedback gain G used for feedback control of the
ignition timing is then set to a larger gain value. The larger gain value
is set such that it varies based on the temperature of the automatic
transmission fluid or other parameter indicative of the engine friction
and/or automatic transmission friction. As a result, the ignition timing
is retarded in a precise manner, the engine speed is reduced, and the
clutch engagement shock is reduced.