I have a 1993 mazda mx6 4 cylinder automatic. Whenever it is warmed up or has been driven for a while the idle speed jumps up to 1500-2000 rpm and I have to keep my foot down on the brake to keep it from accelerating by itself when I'm driving on city streets and whenever I floor the gas while driving or while idling in park the rpms basically drop to zero and the car almost shuts off. It almost shuts off as well when I turn on my a/c. Also the car will not start if I turn it off while it is idling. It runs fine when its cold though. I have replaced the throttle body along with the iac valve and the computer is not giving a code and there are no vacuum leaks that I could find. If you can please help me with this problem thanks!