Hi,
I'm a newbie here.
I have a problem with idle speed on my 2002 1.6 petrol manual focus (145k on clock) after a warm start up.
When I come to a stop (either clutch down in gear or clutch up out of gear) the engine will rev to 2000rpm for 4-5 seconds, then return to normal idle speed 900rpm-ish. If I dip the clutch while moving, the engine will rev to 2000rpm but will not return to normal idle speed until 4-5 sec after coming to a stop. Once at the normal idle speed, any press of the throttle will then repeat the problem.
This problem is only present after a warm start up.
It is never present following a cold start no matter how long I drive for after the cold start (have driven for hours with no problem).
Once the engine is warm, if I turn off then re-start immediately the problem is present. This is repeatable every time.
This has only recently started to happen and is doing my nut in.
Any help is more than welcome!
Thanks

 

Found the problem eventually, it was a split PCV valve hose.
Still confused as to why it only palyed up from a warm start .
Never mind though, fixed now