[blue62]

I go with simplest things first.
coins and other ummm "crap" can get under the shifter where you can't see.
Make sure nothing like that is causing your problem by creating some manner of bind.

When I bought mine it was like shifting a wet noodle.
Perhaps the worst feature on the car.
Replaced it with a cheap short throw shifter.
Not a difficult job to remove the shifter and console to check for a possible cause of binding or replace with a different shifter.

Disconnecting the cables at the shifter then test the movement of the shifter with cables detached would be my next step.
Very easy to do.
Shift cable attachment points at the transmission is an easy check.