I wish you a good evening on all sides! What can it be like if the speed moves in idle mode around 500 revolutions, does not fluctuate or drop? I think this number is just too small, even if nothing happens, I still have the feeling that I am sitting on a washing machine. Can this be due to the spark plugs? Or should I have the speed adjusted to the workshop and the speed adjusted over the control unit? How expensive would that come to me? What idle speed had Is it the Omegas of the year 1994?