Ok i'll try to explain this in the best detail possible.
When engine is cold: accelerates very strong but surging is extremely apparent. It will pull hard from, say, 2000 - 2500 rpm then get sluggish, then pull hard again for another 500 or so rpm.

When engine is warm: surging is not as apparent but it feels like it is lacking power. The power does not feel nearly as strong as when its cold.

Also, when its cold i can hear more turbo whistle than when its hot.
It has a check engine light for vapor evap system or something of the sort
But I believe the acceleration problem is turbo related. It pulls a 9 second 0-60 when warm, which is horribly slow for what i would think this car should be running.
Thanks in advance.

 

The CEL could have came on originally for an EVAP leak..... but now could have stored something else for this current issue.

Sounds like either a turbo or a diverter valve.....

 

I'm gonna go to homedepot and grap a pressure gauge and make a mock boost gauge. I'll let you know what I find.

 

Its steady at 9lbs of boost under heavy throttle, measuring at the intake. Cruising and light throttle it has 0lbs boost and 0 vacuum.
What's normal boost on a stock car?
I'm going to up it to 12 or 13lbs and see how it feels.
Also, my fuel filter is long overdue for changing so i'm thinking it may be part of the problem

 

have you found out anything about this yet? i have been dealing with almost the exact same problem for a while now.

 

Yep, i sold it.

But i did check and it had low boost so check it. Use a bleeder type mbc to fix it and get a boost gauge.

 

Also, join audizine. They are more mechanical over there. This site is more for people who view changing a fuel filter as a big job. Half the guys on audizine have ripped the engine out and did an all out build, which is more like what i do.

 

.......... most of the people on here, are also members on audizine ...........

 

. . . lol

 

Most of the people on Audizine have torn their cars apart and hacked the crap out them. Most of them have no idea what they are doing...... they just do. Most of their cars look like **** and run even worse. Its the same reason why i don't go to the B5 forums, because trying to figure out a problem starts with what the owner messed up installing. Its a pain in the *** trying to deal with it. I'm well versed in performance, but trying to talk to someone who thinks they know everything because they can install a boost gauge is exhausting.

There are a few nice tasteful Audi's don't get me wrong and a few owners who know how to work on them. But they are few and far in between.