Acceleration Problem

[Kwintessence]

I've seen a few of these topics already, but I'm creating this one regardless. I bought an Audi A3 2.0TDI in Automatic from the year 2004. The problem that I am experiencing is when I fully stop the car and attempt to pull off, the car starts to roll because I released the brake, but the gas pedal has a delay of four seconds before coming up with revs. If I don't stop the car, everything works fine. If I am on a straight road, I can gently press the pedal and the car gets there. But when I approach a roundabout or when I need to pull off quickly - there is a four second delay and the car does not rev at all during this delay. The gas pedal was already replaced along with the sensor, the computer was scanned for errors and none were found. 

The only thing that I can come up with is to go to Audi for a diagnosis. Do you have any other ideas?