For about 8 months now my car at start-up would have a shaky low idle for about 10-15 seconds before smoothing out. The problem has of course intensified and is now intermitent while driving. When I am am decelerating the idle will go up. Once I am at a complete stop the idle will get very low and engine will stumble. At other times the car wil drive fine. Sometimes I drive all day with no problems. I took the FITV valve off and checked it, it looked very good. Anybody with suggestions please let me know how to fix this problem.

 

Try an electrical tune up (plugs wires,cap, and rotor) then pull the iacv off and clean the screen on it with brake cleaner and an old toothbrush if needed reinstall and see how its running.