What cause a motor to try to quit running when put in gear but idles good in park?
bad carb adjustment or a dirty carb (Get a tune up or try a
bottle of sea foam from your local auto store) *Some older cars
with lock-up torque converters can have a failed TCC (torque
converter clutch) circuit. This stalls the engine as the converter
is locked solid, connecting the engine to the wheels.
A low idle speed can cause this.