What are some possible causes of high idle on start up, super high about 4000rpm -5000rpm. Once engine is warm, it goes a almost normal, but when it wants it climbs back up at random times.. to me sounds like a vaccuum leak but why would it go so much higher when cold? Car runs really good until it gets to operating temps, then it looses ALOT of power, cant even cruise the car during the day in LA summer heat... any input will be highly appreciated.