Exhaust Emission Systems: Adjustment

With air cleaner installed, engine at normal operating temperature, connect a tachometer and a timing light.

1. Set idle speed at 800 RPM (Man. Trans, in "N") or 650 RPM (Auto. Trans, in "D") and adjust ignition timing to 5° BTDC.
2. Reset idle speed to 800 RPM with transmission in "N". Adjust idle adjusting screw to obtain CO value of 1.5 ±.5%. Repeat adjustment as necessary to achieve 1.5 ±.5% CO at 800 RPM.
3. On automatic transmission models, shift into "D" and check that CO is 1.5 ±.5% at 650 RPM. Readjust speed and mixture screws as necessary to achieve this condition.