Idle Mixture Adjustment: Notes

For both Exhaust Analyzer and Lean Drop Idle procedures, Hot (Slow) Idle RPM and Ignition Timing must be correctly adjusted. See appropriate article in this Section  . Idle mixture is checked or adjusted with engine at normal operating temperature, distributor vacuum line disconnected and plugged, "Fuel Tank" line from vapor canister disconnected, air cleaner installed, air conditioning off, manual transmission in Neutral, automatic transmission (light duty vehicles) in "D" and automatic transmission (heavy duty vehicles) in "N".