Why is the idle speed high and eratic when cold on my renault scenic 1.6 petrol?

-Once its warmed up it still ticks over high and erratically, between 1000 and 2500 revs. if i carry on driving.

If i stop and leave the car for 10 minutes, and then restart, it runs fine, with a tick over very slightly slow.

Its a 2000 16v. model.

I would really appreciate any help with this as its driving me potty, and i know nothing about car electrics,

Many thanks, Martin .well it sounds like and idle issue , it cold be and iac motor u could try to clean the throttle body with throttle body cleaner, and maybe have someone do a fuel sytem service. check ur vacuum hoses. u could have a leak coming from ur intake gaskets. good luck