increased and restless idle 406 2.0

Hello fans! I’m totally desperate with my 406 Break 2.0 Built. 99 When I start it, it goes straight up on 2000 tours, while at the stand it runs completely restless. Also the workshop doesn’t know any more, they changed candles, idlers. The diagnostic device also shows nothing, was there itself. Nobody seems to have a solution for this annoying topic. Who knows more?