Interesting. Mine has had exactly the same thing since I first bought it, in 2012. I mentioned it
here but it has been discussed quite a bit with Dave2000 (because it was his friend's car prior to me, and they looked at it quite a bit) and discussed on both here and other forums.
the thing about my particular problem was that it only did it once it got hot hot, which was only really in the summer here. I had decided it was probably an injector breaking down when it got really hot, and I would get to it at some point..
But then, my original radiator split in about 2014 and I changed it for a Chinese aluminium one with an (alleged) +40% cooling capacity, and bizarrely enough, since then I have hardly ever noticed it again. Prior to that, it could be a right pain in the arse, if crawling in hot summer traffic.
Nothing else was ever been done to the fuel system since, (apart from a filter change at some point recently) and these days, just occasionally, if it's been turned off hot, but then re-started within 5 or 10 minutes, as it starts the fault is briefly there, but one rev of the throttle clears it, and it's gone again in normal driving.
So I am
still thinking it's likely to be some sort of heat-soak injector-y type problem, but my new rad must be holding it a degree or 2 cooler than before and hence masking the issue. Long may that last
But lets be honest, I do expect to have to deal with it again at some point..