alrite evryone.finally got my focus running a lot better than it was.iv checked spark plug connections,cleaned idle control valve and cleaned throttle body.the car is a lot more responsive now(when i put my foot down it just goes instead of farting and splutering for a few seconds)but i need help with something iv come accross.when i rev the car there is like a delay in the revs.say if the car is ticking over and i rev it there is like a hiss before the revs build up.but a mate pointed out to me the other day that he can hear a very faint hiss when the car was just ticking over.does anyone know if this hiss is supposed to be there or have i got leakage somewhere.cheers