Sounds like a fueling problem. Has the fuel filter been changed lately ? can you see bubbles of air running through the tubes to the pump ? white smoke ?
The only other thing I can think of is the cambelt ( or should that be crankshaft sprocket has moved slightly) Theres no key on the crank so if isn't bang on it will cause your problem. sometimes people make an arse of changing the belt and don't tighten the pulley bolt enough which then allows the sprocket to move very slightly.
It's either fuel or timing though, thats my bet.
james
james
October 2009