odd idle need help

The issue with idle surge mentioned in the 5.0 Mustang mag was attributable to problems with the EEC IV which may or may not be applicable to the newer Mustangs since they run the EEC V. It was mentioned in a recent issue (July, Aug 2001) but Im not sure exactly which one. You can check their web site for the technicals.

Given that you are experiencing no "Check Engine" idiot lights, you can assume all the sensors are operating within their stock limits. Id look at the idle bypass valve. On earlier Mustangs, some people have tried drilling small air bleed holes in the throttle butterflies, but I have no information on that procedure past that. So much of the closed loop engine functions are controlled by the engine management computer, its very difficult to troubleshoot idle quality problems without considering that part of the system. Id be tempted to let the deal handle it.