I have replaced the throttle body module twice, replaced spark plugs and wires but still having problems. After starting the idle will go up and down 900-100rpms. It will run fine after a warming up until I get to a long red light. Sometimes at the light it will start going up and down and sometimes even shut down. It will start just fine when this happens. But other times at a red light it will ram up to over 3000rpms and if I do not have my foot firmly on the brake it will try to lurch and throw me into cross traffic. After getting a green light and driving for a 100 feet or so it will idle sometimes and starts running just fine. It does not do this all the time but I never know when I may get thrown into traffic. Can anyone offer me some help on fixing this problem?
I recommend replacing it with one manufactured by either Motorcraft or Hitachi.
Also, disconnect the negative battery cable before replacing the IAC. This will clear the computer memory, and force it to relearn the new idle trims.