Hi all, I have a 97 polo with the updated electrics. The car does everything right, until the air con is turned on. Every time it kicks in when idling the revs jump to 1800 and surge between this and about 2000. I've tried a couple of throttle bodies and map sensors but no change. Vag-com shows no error codes and with each throttle body a tba has been done. With limited info it's hard to diagnose. Anyone have experience with this? Googling has found no useful answers or clues.