Alfa GTV (916) Idle speed too high + squeezing in thrust

Hello Alfa friends! After a relatively long history of suffering (workshop, forums, workshop, forums, forums, forums…) my Alfa GTV (916, 1.8 TS, Bj 1999, 106,000 km) has a new problem again… Now that my idle run has been sawing for months now, the idle has suddenly been much too high for 2 days (2,000 rpm). This especially in warm condition! I also noticed that he is quite jerking when taking gas away (rubbing operation). Lambdasonde, thermostat and spark plugs wurd The throttle valve has also been cleaned. By the way, engine control lamp has never lighted up and it has never gone out (happily) either. Starting it does without problems… I’ve already read countless forum posts, but somehow it could be a lot. I’ve got an appointment in the workshop tomorrow, but before it buttoned me off again 300 euros, I wanted to make myself smart again and with your help narrow down the mistake. So what do you mean, what about it? LMM? Temperatürsensor? Or something completely different? Thank you for your help! Greetings, Dominik