Hi Henry,

Thanks very much for replying to my post. It's great to hear the car has being so well!
I also reached out to a fellow owner in Australia who posted about a similar problem to ours, in fact it sounds identical to mine. He spent a lot of time with AM Dealer trying to sort it out and eventually someone spotted that one of the vacuum hoses wasn't connected properly and this solved it for him.
I'm probably going to have new plugs and coils next year so will get this checked at the same time.

Thanks again for the reply!!