John Speake

OK Chris. I should of course have said "faulty closed throttle switch is not going to affect off line performance".

I expect you have read the thread on failing WOT switches ? It may be that when cold, some of these faulty WOT switches do meausre OK, but fail with heat.

Try a battery reset, and see if the car seems to pick up better, if so, this suggests that a knock sensor may be the problem.