Abstract: A carburetor for an internal combustion engine has an idle or low speed system in which air is bled into the idle fuel passage. An air bleed valve member controls the amount of air flow through an air bleed port for the idle fuel passage and a diaphragm operated control is connected to the air bleed valve member to control the movement of the valve member. The diaphragm operated control has an air chamber on one side of the diaphragm and a vacuum chamber on the other side of the diaphragm with a restricted opening between the air and vacuum chambers. Upon a rapid engine deceleration to an idle position, the air bleed valve member is moved to a position to provide maximum air flow to the idle fuel passage for a limited period of time until the pressure is equalized between the vacuum chamber and the air chamber through the restricted opening.