This is a detailed video showing the restoration of the warm running device (WRD) on a 1965 Mercedes 230 SL. The video goes on to explain exactly how this device regulates both the fuel and the airflow as the engine warms up to temperature. If your Mercedes Pagoda W113 has a rough idle or difficulty starting when cold, this video might give you some ideas on how to fix the problem. The WRD is often mislabeled as the cold start valve (CSV) but the latter is a different part of the car covered in a later video.