Check for vacuum leaks and check the idle air control valve.
February, 4, 2013 AT 9:47 PM
Hi guys. Excuse me for butting in. This is a real common problem with an easy fix.
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.