How do you adjust idle on 89 Seville Cadillac?

To adjust the idle on a 1989 Cadillac Seville, start by warming up the engine to its normal operating temperature. Locate the idle adjustment screw on the throttle body; it's typically marked with a colored dot or arrow. Use a screwdriver to turn the screw clockwise to increase the idle speed or counterclockwise to decrease it, while monitoring the RPM with a tachometer. Ensure the idle speed is within the manufacturer's specified range, usually around 600-700 RPM in Drive.