Weird response to extra gas pedal action?

Not sure how to describe it better, but the response feels a bit like an automatic and it's a stick shift..... when I press gas to the floor (I have to do that on occasion), now I get a slight hesitation as the rpm's go up by about 500 or so. It last about a second or so, and then just as suddendly as it started it stops and drops the RPM's back to the point they were at and I got full throttle....

Btw, it's a 98XJ with 130K on it with no work to the drivetrain (SYE don't count ) except the religious fluid changes, and the AX15 has been getting it's GL3 as prescribed.....

Any ideas anyone?
Btw, recent work on the XJ is CPS sensor and of course it just came from Moab, and it seems to be something that I did notice after returning back... not sure at which point I became fully aware of it though...

I would point the finger at the beginning of the clutch disk slipping.The RPMs going up when you mash it rules out a throttle problem,so the only thing left is the clutch.
Are you down shifting to accelerate and then have it slip when you power up ?
Could be the release bearing is hanging on the input shaft?
HTH
Wayne

I was very much afraid of that.... short of taking of the tcase and tranny to get to the clutch is there any other way to test the clutch's condition??

Is there an inspection plate on the bottom of the belhousing ?All mine are autos so I don,t know off hand whats there.
Wayne