Acceleration and hitting a wall

[Peer Oliver Schmidt]

List,

I have a problem. I have a chipped + new turbo (mtm) 200q20v. At the
beginning (1,5 years ago) everything was fine and dandy, car pulled very
strong.

The last couple of month most of the time under acceleration it seems as I
hit a wall for a second, before the car accelerates again. Sometimes it does
not continue the accelaration but continue to studder. Doesn't matter if it
is hot or cold. Slow acceleration works just fine. I can still hit the
maximum on the bar gauge as before. Gear does not really matter. Most of the
time, of course, it happens in fifth gear accelerating out of an autobahn
entry or after some slow traffic because of road work.

Could this be a fuel problem? My local Audi garage can't find any codes. Any
ideas i should try? I am a little hesitant to drive 500 mls one way to mtm,
to have them fix this.

Any and all help is greatly appreciated.

rgds

Peer Oliver Schmidt