Volvo: 1998 VOLVO XC70 WAGON, volvo xc70, vacuum leaks

Question
At random times, but only when it is cold, my 1998 Volvo XC70 Wagon will only reach idle speeds until it is warmed up.  There does not seem to be any pattern to when it will do this other than I have only had it happen during the winter months and at random temps and times.  Any help would be appreciated.  Thanks.

Answer
Mary,
Check for vacuum leaks. Read any fault codes and take care of those. Is the heat as hot as it has been in the passed? I have seen some t/stats break and maybe the engine is not warming up enough, so the control unit things that the engine is too cool and raises the idle due to a richer fuel mixture. Remove and clean the throttle hosuing, getting all the carbon out. Make sure that the hoses to the idle air valve are all in good condition.