Mustang Hanging, High Idle #1 of 3

This is part one of a series on Mustang hanging idle, high idle. This is a common issue that isn't fixed very often without tuning. My goal is to teach how to pinpoint and resolve the issue. Tuning it out is the last resort.
The two example calibrations used are the 2003/4 Mach 1 and the Foxbody A9L.

[@dr.john-markcain4946]

Does type of MAF matter? IE PROM 75 tube v 77?

[@tuninginnovations5481]

It doesn't matter. Its a harness issue. Resistance in the signal wire creates a delay. Pro-M Mafs are usually good.