Idle control valve vs. air slide valve

Hi Folks....
Have a problem with a high idle running between 1200-1500 rpm in neutral with temp at 80 degrees. Have read about the idle control valve being a possible cause but have discovered that for a 1989 560SL, my parts book lists a "air slide valve" instead of a "idle control valve". In any event, any advise on my confusion, or even better, what do I do about the high idle ?
Got AC problems also, but I'll save that for another day !!!

Thanks,
George