help identifing component on 82 380sl engine
 

Hi
well the car is running great, a pleasure to be back in a Mercedes,
My question, in the engine compartment between the cruise control actuator and the idle speed control there is a component with an electrical connection, two metal lines and two vacuum ports, the bottom vacuum line is connected but the upper one just has a rubber elbow on it and is not connected to any thing, what is this device and what line should be connected to the top vacuum port? I have looked at the manual and the only view I can find is in the part about setting the idle speed control with no reference to this device
thanks

a warm up regulator and the hose is a vent