question? why has the fuel pressure regulator been messed with?ie/ my saff is running greens and fuel pressure has been raised so that it doesnt run lean on high boost.if your car is standard,and you are looking for a base setting.warm the engine up to temp,turn the screw anticlockwise untill the engine starts to hunt,that means the mixture is weak.then turn it clockwise untill it idles evenly.drive to your nearest mot station and get the emmisions checked.if it is ok then drive to stu, but keep it off boost.might be a slow journey but cheaper than a melted piston