Airflow Sensor & Mixture Control Unit
- Detach and remove intake cowl at mixture control unit and throttle housing. Turn ignition on for about 5 seconds, then turn ignition OFF. Raise sensor plate by using magnet or pliers. As plate is slowly raised, resistance felt should be even throughout range of travel.
- When sensor plate is quickly pushed down, no resistance should be felt. Do not allow plate to scrape on air horn wall. If necessary to center sensor plate, loosen centering bolt in middle of plate and adjust.
- Check sensor plate height. Plate should be even with beginning of taper in air cone. If plate is no more than 0.019" (0.5 mm) deeper than edge of tapered area, adjustment is not needed.
- To adjust height of sensor plate, remove mixture control unit and bend spring beneath plate assembly. If sensor plate is too high in air cone, engine will diesel (run on). If plate is too low, poor cold or warm engine starting will result.
- Check for sticking or binding fuel control piston (plunger) in fuel distributor. Remove fuel distributor, remove plunger and clean thoroughly with solvent. Plunger binding or sticking is evident when resistance to sensor plate movement is uneven.