I have a problem with idling. It won't unless you give it some throttle. There are no pending codes, no MIL light. I have cleaned the throttle body. I have replaced the IAC twice. Both times it solves the problem for a short time (30 minutes to 10 hours) then it goes right back to the same no idle condition. I pulled the master cylinder vac line to keep it running at idle and I have power on all 4 of the IAC wires (pulsing). I boosted the battery and cranked the motor while watching my attached volt meter. Never went below 12 volts. What is left to check?
Sounds like the battery might have been disconnected or run dead recently. If so, the Engine Computer lost its memory and has to relearn "minimum throttle" before it will know when it must be in control of idle speed. It also might not give you the normal "idle flare-up" to 1500 rpm when you start the engine. To meet the conditions for the relearn to take place, drive at highway speed with the engine warmed up, then coast for at least seven seconds without touching the brake or gas pedals.