1998 JGC RPM spike while at highway speed
 

Hi All,
I have seen a couple of posts some years back on this topic but no
confirmation of effectiveness of fix. Hope one of you can confirm.
Here is the problem:

I have occasionally experienced that while driving my 4.0L at hwy
speed +/- 70 mph (with cruise control and A/C on, sometimes under very
slight uphill incline) the engine RPM will surge by 2-300. It acts
like its attempting to downshift but then re-engages in overdrive
after a second or two.

The fix I have seen proposed is to check and adjust the Throttle
position sensor. Does this actually correct the problem? Also, could
this condition lead to transmission or torque converter damage if left
unchecked?

Thanks for your generous input and advice.
-Scott