Audis8265

Hello guys
I have big problem got my s8 40v with vibration under acceleration first i thought it's the hanging bearing or something like that but then i noticed that engine does not have power vibration comes from 2k to 4.5rpm then it disapears im thinking about 1 or 2 ignition coil may do intermediate missfire but vcds doesnt show any all groups which should count missfires show not allowed any other ideas how to check them? Car has lpg system on both fuels is the same. BTW 0-60MPH tim is 9.5s

Audis8265

Spark plugs new, o2 sensors new, mass air flow sensor look like good but not 100% sure. Did compression test all cilynders are above 7bar on cold engine