Happened to me twice now! Driving along, engine temp etc upto 'normal', drop her down a cog or two, foot down to overtake and hardly any power! Car boosting to 5psi max. Pull over, turn off engine, restart. Set off, foot down and now all power back and boosting to 10psi then quickly drops to 6-8 psi.
initially i though 'f' hose or spider hose, but when i restart the car its fine. like i say, only happend twice in a week now???