I finally got round to changing the plugs on my supra today and found that 1 was quite damp and the other very wet. It looked like fuel as opposed to oil and was very runny. This was just on two of the plugs, the worst being 4th plug (1 through 6 if your looking straight at the car from the front).
The plugs were Denso ones and didn't look in the best shape, would a plug that isn't working as well allow for excess fuel to not be burnt off?
On another note. Should a n/a make a "sucking" or "wooshing" type noise when you gun it? It almost sounds like my old turbo when it was spooling.....