have a 93 xj6 v.p. [love my jag] and ahve the most annoying problem. When Im in car goes over 50 mph [what feels like the torque converter] seems to lock up, so that when you let off the accel. the car surges, and then does the same when accel. again. its driving me nuts cause it feels like having a standard trans and letting off the accel. at high spped in high gear. help?