What is the best way to start trouble shooting a low idle on a 350 TBI? It will idle fine at first start of the day, but as it warms up and sits it will just barely idle. Turn on the A/C and back out the driveway and by the time I get it in Drive, it quits. Goes fine up and down the road. Idle seems to be the problem. Where do I start? I assume that I cannot change the idle on a TBI and that all of it is controlled by the MAP and other sensors. I apologize in advnace, my knowledge of the TBI is VERY limited. Vehicle is a 87' V20 Suburban 4X4. Thanks to all those who can help.