my vauxhall vecra estate 2.0 turbo d(year)2000)wont rev high?

vauxhall vecra estate 2.0 turbo d(year)2000)wont rev high,the engine mannagment light is on and it smokes when revved,it happens after about 20 miles or so i think or when it gets to full temp. ive been told its the pump but im not convinced lol.in passed expierience when a derv pump goes it goes.any way,ive cleaned fule tank out n changed the fillters car ran great for about 20 mile then went in shop came back no revs eml on again wtfck dose any 1 have any idas cheers