I coppied the text and posted below, I couldn't copy the pics.....
Good luck and welcome to DT....
The idle is set in the PCM by a idle target parameter. Installing a newer throttle body or cam cam change what the PCM needs to see to stop surging or erratic idles.
The picture above is a stock plug in a stock throttle body, to adjust the throttle plates angle, this plug needs to be removed. On the Flometrics throttle bodies (right), all you need is a Allen wrench to adjust. Note: some of the Flometric TB's have double set screws in the throttle shaft adjustment.
To set the throttle plates correctly, the vehicle needs to be warmed up for at least 5 minutes to ensure it is in closed loop. Once done, the IAC port (shown below, left) needs to be blocked off with your thumb, then turn the adjustment screw clockwise to open the plates, counterclockwise to close them, until the rpm sits at 800 rpm steady. Remove your thumb from the IAC port and the idle will climb up and then return back down to norm. You have just set your IAC count to 30-60 counts. This is a good number for the IAC to sit at without having to swing wide to recover from extreme idle conditions such as braking or WOT.
If you have a scanner, adjust the IAC count at idle to be between 40-60 counts. You can also install a false IAC sensor in the plug to fool the PCM into believing there is a idle control when you are setting the idle by the throttle plates directly, the false sensor will operate while the original IAC motor sits idle in the throttle body. This eliminates the long decel times after rev'ing the throttle.
This is a picture of a Flometrics 58mm throttle body IAC being plugged for throttle adjust while idling around 750-800 rpm.