Idling and start issues

I start up my b8.5 s4 and then it goes up in rpm in a second instead of immediately like in the video. Like some sort of delay. Also my rpm’s when I’m idling don’t stay constant it sometimes revs up to 1000 from 850 and then falls down from 850 and revs up to 1000 it’s very weird. If someone knows what’s wrong please let me know.