Hi, I would like to ask all the members who have a Jaguar XJ6 4L Vanden Plas if anyone has come across this throttle problem, it begin a while back, no throttle on cold engine and Ok after warm up, the last time while driving the engine begin to speed up on it's own, after shut down then restart and now no throttle upon depressing the gas pedal, but in neutral will accelerate if I move the throttle shaft by hand. If I disconnect the TPS the engine will increase the RPM to 900 to 1000. My MT 2500 Snap On Scanner will not communicate and no code are detected.

 

The butterfly on my throttle was corroded and started to stick open, which caused my 97 VDP to accelerate on its own. I had it replaced and the throttle body cleaned and that fixed the problem. You might try that...

Good luck!