56 Plate A3 1.9TDI WITH IDLING PROBLEMS

[jebus109]

Hi i've newly registered with the site and have an 56-plate 2.0TDI A3. Recently when starting the car from cold it does not idle properly. When sitting at the lights you can feel the car shuddering and the engine revving up and then dropping down to the point where you think it will cut out. The strange thing is once the engine is warm or if its moving normally everything is fine. It's only from a cold start the idling problem occurs. Taken it to the garage and they say there's nothing wrong with it but my brother has borrowed the car and noticed the same problem. I've read about the guy with similar a similar problem on a 2.0TDI but was wondering if anyone had any ideas? Any help is appreciated

thanks

SORRY JUST TO CLARIFY THE ENGINE IS A 2.0TDI

jebus109