That is a great reply, allowed me to google more specific, and found this from the workshop manual (of course, where else? ):

Jaguar Workshop Manuals > XJR (X308) V8-4.0L SC (AJ26) (1998) > Transmission and Drivetrain > Automatic Transmission/Transaxle > Downshift Switch, A/T > Component Information > Adjustments

Pretty much sums up your advise, so thank you very much for the help!
Will get into it tomorrow.

Well, that really was a 1 minute job...

I found out the 1998 N/A does not have a kick-down switch, but just a plug (this of course only after removing the carpet etc ...).

Anyway, I presume the 90% setting also applies (done cold), and I will see where it goes when fully hot.
There is much thread left in the knob, but so far I can't find anything on the correct setting for a N/A.

Oh ok. I completely forgot about the N/A cars not having a kick down switch but at least your in the know about that throttle stopper. If it were my car, I'd adjust the throttle opening percentage as high as I could get it. I believe I turned that stopper all the way down on my car and was like 92%.. If I was feeling sporty (which I'm not), could I take the stopper out and modify it to get an even higher number or even 100%?? Possibly, but I'm not looking to get every ounce of hp from a 240K mile engine.

This morning I also took off the air filter housing, cleaned the MAF one more time, replaced a gommet under the housing (which caused a very strange connection towards the TB), bent the MAF connector pins a tiny bit, lined up everything carefully tp prevent leaks, made sure the accelerator cable had just enough slack, and did some other small clean up work.

Then I took the car out this afternoon, a pleasure to do as we have some incredible warm and sunny days, almost back to summer.

Well, altogether I am very happy.
The car runs a slightly lower rpm on idle (the cable was just a 1/2 turn too tight before), some ~635rpm, and picks up beautifully.

And although I normally hardly exceed 2.500rpm, the extra power at full throttle is noticeable.
Not a surprise as the less than 70% was really restricting the airflow.
I will adjust the the knob a bit further and see if I can get all the way down to 100% ... why? I really have no idea, it sounds good perhaps ...

Then, the best, I got my LTFT's back to ZERO, and within a range of 2% during the whole of driving, flat, hard, mountains, downhills.

I loe this car, and thanks again, Addicted2boost!

Generally the PCM checks the value and doesn't expect 100% so I'd leave it as it is now. It sounds fine, why mess...