A3 Breathing issues...
 

Right, my first post here.
Introductions out the way; I'm Simon. I'm 20. I'm from London.
Done.

I got a 1.6 2000 (W reg) A3 about a month ago.
Bargain price with a few bits wrong with it.
Sounded to have a missfire, so i got to work straight away on the head gasket, timing belt etc.
Full service was done.

However, since i did that complete service on Wednesday, it still seems to have a slight missfire and absolutely no power on low revs.
Once it starts screaming, it's fine.

Anyone got any ideas?
I'm thinking maybe the timing could possibly still be out a touch.

Any help would be greatly appreciated.
Many thanks,
Simon