On my '98 XJR, when I move the shifter from D to 4, nothing happens. The 4 doesn't light up and the car doesn't shift. If I push the shifter up toward the 3, I can find where 4 lights up and it shifts, but it doesn't do it right in the corner, on the detent where it should be.
Is this adjustable? Something out of whack?

 

Shifter cable sounds to need adjustment.

 

There are several micro switches under the shift-cover, and although I am not sure, I think one is related to the 4-3-2 position of the shifter.

It is actuated from underneath by the circular (and moving around by means of the shifter) inside cover (the one with the brushes).
You might check if this is related, surely someone will chime in on this.