First, try alt.autos.audi with the same question.
Perhaps also look at audifans.com or audiworld.com for discussions of the topic.
Also, and I don't know if this is the issue, but there was a change in the number of teeth in the belt around 1998 or 99,
For people (i.e., not dealers) who do this all the time, try ecstuning.com
I'm relaying this information second hand, so I hope I have the details > correct.
>
> A friend of mine has a 1999 or 98 (cant remember for the life of me) Audi A4
> 1.8L turbo. The timing belt is being replaced, but one of the cam sprockets
> does not have a mark or arrow or dot like the other cam for lining it up
> properly. Thus, the mechanic had to guess where it should be, and it wont > start.
>
> Anyone have a diagram of what the cam sprockets should be set at? The only
> reference he has is the keyway on the backside of the sprocket.
>
> Ryan.