Here is some input in Ford Forum to a guy with same probem as mine . I was leaning toward the TPS. Any comment on that?
(This was the advise to the guy with problem)
There is an electrically controlled valve that lets air bypass the butterfly. That is how the idle speed is adjusted. The TPS
and temperature sensor are in the same circuit and electrically affect the idle speed. To troubleshoot the sensors check them with a meter. You need a meter with a needle to check the TPS and then it's still a little voodoo. You can check the bypass valve by making a gasket that blocks airflow through the valve. Good luck.
(This from the guy with problem)
I assume your talking about the IAC, (Idle Air Control) valve
? If so I had already changed that out last summer without any changes.