i know this has got nowt to do with a prime pump but are you sure thats the problem

as if its only revving between 2500-3000 rpm it sounds to me that its more likley that the pipe to your turbo is either loose or has a split etc in it,as this would make it lose power & stop it revving.as trugga said the primer pump is for bleeding the air out after filter change etc etc
i,ve said this before,i dont even use the primer pump,it is much easyier to cut the fuel line from the filter to the pump & insert a hand pump,so if you ran out of derv or after a filter change 2-3 pumps sorts it & engine fires as it should........