Trainer controller? Cold type controller? Problem with 270cdi

Moin moin, I have a little problem with my cube again after a long time…. it has crept in since 10,000km the following. Every time the car is cold it runs round… or does not really hang on the gas… Start and so on everything is unproblematic… when I then start slowly, and he has reached the 30kmh in the village and hangs on the accelerator, Then man notices that he runs round. I try to express it with letters: Quasi makes the engine sound not wuuuuuuuuuuuuu and he drives normally at the speeds for which I press on the gas but when he has reached the speed he makes wuuu….wuuu….wuuu…wuuu This of course only notices at low speed. If I drive faster e.g. on the federal road or so everything is fine. Even if it is warm, it is immediately gone…. When I noticed that the first time he started the next day no more… we read out mistakes. d then camshafts and crankshaft sensor implausible values and additionally still accelerator sensor sporadic. I then switched cams and crankshaft sensor and it immediately jumped again. And also ran since. Only this wuuuuuuuu wuuuuu is always there when it is cold. Can this be connected with the accelerator sensor? Or does someone have another idea? Greetings from the north year 2005 and 160.000km