Very high idle, intermittent problem

Thank you for taking the time to address my question.
As you stated the TPS voltage output(signal) will not cause the idle to go that high. I don't know enough to either accept or decline that statement.
You further stated that the throttle body plate is not seating (correctly) in the bore.
You suggested that I clean the throttle body ( I have done it and also cleaned the IAC sensor seat) I will do it again, just in case the first time didn't clear everything.
Would you help me understand the following:
Is there a command from the PCM that actually opens the throttle or is this event done strictly by the accelerator pedal cable?
When I start the engine (cold). It goes through the warm up process. Around 1300 RPM and then it comes down to around 750 RPM. This period the engine is "normal", once it warms up the RPM starts to go all over the range (1,300 to 3,400 RPM's). The only change I can perceive is the increase in temperature ( I don't know if there is a sensor that will trigger the PCM to increase RPM, maybe through the IAC valve. I don't have a guide to what should the IAC voltage should be. It would be great if you can provide such information, so a can back probe the IAC and see what the voltage is doing.
I suspected two things the PCM is at fault, or this is a mechanical problem. The mechanical problem would be if the throttle body plate is somewhat damaged (out or round or warped ) or the actual throttle body has been damaged and is not matching the shape of the plate. As temperature increases the dimensions are changed enough to cause binding between the throttle plate and body causing the plate not to seal completely and avoid a "leak" causing the PCM to read a lean condition and injecting additional fuel causing the RPM to go higher. I don't know for sure what commands the throttle plate to open other than the accelerator linkage or in the absence of plate opening, if the IAC will provide the additional air. There is no question that air is coming in somehow, the engine is a air pump, without the additional air it can't increase the RPM.
Any clarifications will be greatly appreciated.

In this case there is an actual steel cable that rotates on a cam and opens the throttle plate and that is why I asked if the ECM has a way to command the opening of the plate. This is not a step motor controlled throttle. On one side there is the TPS unit and on the other the plastic cam with the steel cable, attached to it, that is operated by the accelerator panel.
I can't tell how the IAC sensor is positioned, therefore I can't figure out if the air is coming through the IAC or the throttle plate. Another possibility is the EGR valve being open and letting air in once the engine warms up and the amount varying because the EGR valve may be getting stuck on different positions.
Thanks for the help.

Thanks again.
Is there a way to check the ECM without a scanner?
I don't have a scanner at this moment.
I'm looking at Autoenginuity. The scan tool is about $250.00 with domestic package about $800.00 and with Domestic, Asian and European packages it is about $1,500.00. I was looking at the parameters that this tool, with the Enhanced package for GM, it shows over 100 parameters. Do you have any comments on the Autoenginuity scanner?
Thank you.

Thank you, I will look for someone to check the ECM.