Yea looneytune just PM'd me a good bit of help as he was having nearly they exact same problem and fixed it with tuning, so i think its a tuning problem, i have tried resetting needles, tuning from HSN first or LSN first and all that jazz. The engine isent in the buggy atm but the next time i get a chance ill be sticking it back in there and and have another go at tuning it properly with looneytune's advice and the other advice given here.
Cheers.