1. Park your car on a level surface and turn off the engine.
2. Locate the idle speed adjustment screw. It is usually found on the throttle body assembly, which is located on the front of the engine.
3. Start the engine and let it warm up to operating temperature.
4. Use a screwdriver to turn the idle speed adjustment screw clockwise to increase the idle speed or counterclockwise to decrease it.
5. Adjust the idle speed until it stabilizes at the desired RPM. The recommended idle speed for a 1993 Nissan Altima is 750 ± 50 RPM.
6. Test drive the car to make sure the idle speed is stable and there are no issues with the vehicle's performance.
Note: If the idle speed adjustment screw does not have any effect, it may be necessary to clean the throttle body assembly or check for vacuum leaks.
