Maybe... on my GEMS the plug from engine harness to gearbox (behind left rocker cover) was unplugged. On the nano it gave me a message to say something like "invalid throttle angle data", when I drove it the gear changes were very clunky, although it did change below 2600. Take a look at the tps/ its connection, most likely. Just a thought, no doubt there are other, scarier, possibilities :o)
50th RR 1998 4.6L GEMS, 50th Defender 4.0L GEMS, Nanocom Evo (P38/ GEMS)
Formerly 200Tdi 90 CSW and SWB Series 3
SW London