I'm in South Devon mate. It's going in Wednesday for a smoke test and to have the Forge DV removed and Revision G installed as a replacement. I'm always trying to self diagnose and have been using the forums for years, more golfgtiforum than anything else and as you say it's a nightmare because it turns into a guessing game. But it's only people trying to help, which I really appreciate. I'm sure it's something simple. N75, DV, torn vacuum pipe etc.
Thanks bud