Choke valve
![M21i engine bay original parts](/Images/godic/202501/04/M21i_engine_bay_original_parts2222.jpg")
A choke valve is a type of valve designed to create a choked flow in a fluid line in an automobile. The viscosity of the fluid passing through the valve is irrelevant in understanding how the mechanism works. The rate of flow is determined only by the ambient pressure on the upstream side of the valve.