i've got a 93 wrx[import] and in the last couple of weeks i've come across a problem, when i accelerate the turbo comes in then it kind of judders then it shoots off again.has anyone had the same problem? or know what the problem is

 

some people will say maf, some will say ignition (plugs//coil packs)
I had the same problem a while back, changed the plugs to new ones, correctly gapped them and it is now fine. Also make sure you use super unleaded otherwise that could cause you problems.
Due to the age of the car there is a possibility that the coil packs are on their way out

 

forgot to mention it could also be a clogged up boost solenoid