This invention pertains to an automatic disconnect of the engine operated spark advance until the engine water jacket temperature has reached a predetermined temperature to reduce smog producing emissions and heat up the engine more rapidly. An engine water temperature responsive valve connects closed throttle valve suction, from the manifold to a spark control actuator to retard the spark timing when the water is below the predetermined temperature and connects closed throttle valve suction, when the engine jacket water temperature is above the predetermined temperature to the actuator to advance the spark timing.