i've got a problem with a Ford fiesta 1.25, 1999, and was wondering if anyone can help please....... when coming to a halt, the revs are slow to return to a normal level, of about 900rpm...... but when the engine is "revved" up, without moving the car.....the engine just seems to return to normal engine speed right away. car seems to run ok, with no other obvious faults..... any ideas please..... Many thanks.