when its warm, my 89 sho starts right up and drives fine instantly. when its cold, it starts right up, but will go down to a 600RPM idle and stutter a bit. when I try to drive right off the bat it has a severe hesitation no matter how much/little gas I give it. I let it warm up for 7 min and its fine (unless I gun it, then it shakes a bit, but thats pretty normal for a cold, 14 yr old car). in warm weather none of this happens. also, after a warm up time the idle reurns to normal also.