2007 207CC 150 bhp Turbo - already had a timing chain kit and the head decoked. Idles fine, cruises along fine but ask it to accelerate and it holds back and surges. No fault codes present. Plugs are new as well.
Seems to be fixed - poured half a bottle of Forte injector cleaner into 15 quid's worth of petrol and it's a lot better. Weather permitting will give it a good 80 mile run tomorrow but it's looking very promising.