Hi,moin My convertible starts spinning slowly, in high gear (automatic) at low speed.It is jerking with speed variation of up to a partial stroke,200 revolutions.When I speed up, and in all other gears,no problem, it runs perfectly. Audi 80 Cabrio engine 2.6 ltr.150 hp spark plugs new,after error detection I am grateful for any help MfG.P.W.