Clean idle controls?

Hello to each other, for 2 weeks I am proud again owner of a 16V year 91. I am very satisfied with the car and had some luck to get such a well preserved car. At the moment he stands at 182000 Km and runs quite well. Now to my only problem, sometimes he runs out of me in idle. If he is cold, there are no problems, even if he is warm driven, the small one purrs, but when I go out in cold condition and turn out the car on the road after about 3 minutes, d a I go shopping, then he has an idle problem and goes out constantly as soon as I am at a crossing and the clutch kicks the speed into the cellar and it goes out to me. After 5 minutes everything is fine. What could this be about? I heard that it can be on the idle control, looked for something on the internet and found the following for cleaning the Llr: At the C20XE: -Put off hose at the SFI box at the bottom right. -Start engine and hold something on gas, as this s -Ventil cleaner in small sips in the hose tip and let the engine gurgelln. -Don’t scare it Qualmt then something from the exhaust. -Complete bottle slowly empty darewin -Just let something run in idle until it no longer squalmt -Tube again What do you think about the method?