[grizzly]

The problem that remains relates the car when it idles. After a couple of miles running and sitting in traffic the car idles at about 8000 rpm, but every 2 or 3 seconds it appear to miss a beat and the car kind of wobbles?

8000 rpm? I assume you mean 800 rpm.

Except for the knocking noise I'd say it's probably not something mechanical, something like a sensor problem or boost leak. Knocking noise is possibly a mechanical problem but see if you can solve the cheaper problem first and get it running right and see if the knocking goes away.

Since they cleaned and checked the injectors these are probably not causing the problem. Hesitation and a problem revving at 1800 rpm is probably a sensor problem or boost leak causing the car to mistake fuel or air quantities.

Is the cam timing good? Is the timing belt on spot? The car changes the fuel timing itself but the cam timing is controlled by the timing belt.

What engine code is this anyways, we didn't get the TDI in Audis