Correct computer for 1990 Audi 100 2.3 5cyl is Bosch 0 280 800 308.
1989 thru 1991 100's will have it, and probably more vehicles beyond that group. It's the number that matters.
Clean, still-sealed, from known-good running vehicle preferred. Someone "fixed" the one I have now, by the looks of it on a back porch or kitchen table. It has intermittent dementia...lapsing into fits without notice or provocation.
It's the one in the passenger-side kick panel (on a LHD vehicle).
Let me know if you have one.
Jeff