Had the same problem with the '96 2ltr. The cup of the ball joint at the gearbox end of the selector cable has worn and popped off. You can do a tempory fix if you put it back in place and then "wire tie" the two control cables together. If you look down into the engine bay just behind the battery box you should be able to see the problem.
I can't get the trip computer to work on my '96 2ltr Ghia. It shows how many miles to fill up, but thats all it does! On MPG it shows --/-- and on trip time it shows the same!! Anyone any idea's? Thank's Peter. :)