Hi all I have a 2.0 hdi relay and its purely to take the bike on track days and use the off trip to work to keep it in use its got 148k and the and it doesn't clock miles probably has about 170k on it since it stopped clocking, Anyway took the old girl from home (Woking Surrey) to snetterton the other week drove up one evening its always been a bit funny performance wise I can put my foot down at it goesbut then as I'm about to changre gear say around 4,000rpm i get a load of boost come in and it goes really well but it doesn't always happen and when it doesn't happen I'm not getting that nice amount of boost, anyway stopped at a services to grab dinner on my journey was stopped for about 25/30 mins jumped back on the carriage way and as I was accelerating it was de accelerating then accelerating then backing back off the whole time I had my foot down, for about 20 minutes I toyed about with my throttle positioning flooring it etc nothing changed its mind it continued, was fine on the way home the next day but I can't figure it out, due to work I've not had chance to really look at it although I know the vaccume lines are starting to perish I can't see a form of boost leak although not thoroughly looked, Anyone shed a light? Thanks in advance.