Adjustments should be performed with the air cleaner removed and, on models so equipped, with the air conditioning turned off.
- Remove the air cleaner.
- Connect a tachometer and a vacuum gauge to the engine, set the parking brake, and place the transmission in neutral.
- Turn in the idle mixture screw(s) until they gently seat, then back them out three turns.
- Start the engine and allow it to reach normal operating temperature. Make sure the choke is fully open, then adjust the idle speed screw(s) to obtain the specified idle speed (automatic transmission in Drive, manual transmission in Neutral).
- Turn the idle mixture screw(s) clockwise (in) to the point where a 20-30 rpm drop in speed is achieved-this is the lean "drop off" point. Back out the screws 1 / 4 turn from this point.
- Repeat steps four and five if necessary.
- Turn off the engine, remove the gauges, and install the air cleaner.