its not got a turbo :S
erm apart frm that guy who has had car since 1997 has done most of servicing apart from fuel filter lol !!
its never been changed in all 10years of him owning it lol!!!
and looking thro sierra manuals they say 'fuel filter choked' or possibly 'air leak' or 'injection problem'
there is a few more but i cant be bothered right them up !
but ive got new fuel filter and gonna fit that today!!