2001 F-150 4x4 ext. cab
Normally there is no connection between throttle an shifting in this manner.
I would have some one you trust to do the shifting while you look at any movement of the throttle via the cable.
If you do see it, there is some type of interference with the cables and linkage at some point.
The only way a motor rpm increases is the introduction of extra air by some means. The throttle body plate is forced to open or the IAC opens for some reason.
Extra 'gas/fuel' only increase rpm a small amount.
Look for these types of issues.
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As related to above:
Remember the Toyota run-away issue being blamed on the computer?
Can't happen in "the way it was reported".
A foot or carpet stuck the throttle open in some manner.
FORD after 04 has electronic throttle control with layers fail safe software and hardware to prevent such happenings. There are always very rare conditions for it to happen on any veh.
Good luck.





