September 12, 2011, 3:22 am
[quote name='peteq' timestamp='1315778682' post='143783']
Got 1.8 petrol focus. Today when starting from cold, revs fluctuated between about 450-700 up and down etc. Now normally it idles approx 1200 when cold then settles as it should to approx 750ish. Any way back to story, revved it a bit then it settled down. Has anyone else had this or any suggestions what it could be (dodgy throttle switch / idle valve etc etc etc?)
Hi Pete, assuming you use it daily, what was it like today when you started it? I would suggest seeing how the problem goes and if it plays up again it could well be your idle air control valve, this is in charge of the RPM when the engine is cold and what you describe sounds like it could be faulty, or simply dirty.
Some people have had success removing these and then giving them a clean out, you can buy special cleaners or just use some a little bit of petrol.
Let us know how it goes