A8 engine hesitation

[pebul]

I have an A8 LWB 4.2 TDi Quatro and since delivery have had a slight hesitation (under certain circumstances) when asking for quick acceleration. It is as though the fuel is not getting through at that particular point but by coming off the throttle and then back on it clears and "take off" takes place! This is a bit disconcerting for passengers an, if,when entering a roundabout you see a gap and go for it,the hesitation is dangerous! Has anyone else suffered this? I have had the car "chipped" by QS in East Grinstead which has given the car more flexibility mid range but has not stopped this annoying "flat spot"
Any ideas?
PS: This is MY first post so appologies if I have gone on a bit!
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[MFGF]

Hi - welcome to VWAudiforum!

You're probably best posting your question in the A8 section (and searching in there to see if the question has been asked before and answered too).

Good luck!

MF.