Correctly setting your idle speed 1980 - 1988
From the AMC Technical Service Bulletin 12E460
The idle speed may be too low or inconsistent on your 1980 - 1988 Eagle automobile. If this condition exists, the following items must be adjusted to obtain proper engine operation.
Fast Idle Speed
Curb Idle Speed
Sole-Vac Throttle Postioner
Adjustment is as Follows:
1. The engine must be at operating temperature and all electrical accessory switches in the OFF position.
2. Remove the air filter assembly -- make sure to mark where any vacuum hoses connected.
3. Set the parking brake or better yet block the wheels. Shift automatic transmissions to PARK and manual transmissions to the NEUTRAL position.
4. With the ignition switch OFF, connect an ignition timing light to the number 1 spark plug (Figure A) and tachometer to the coil ignition negative terminal (Figure B).