My supercharged 1990 has developed an occasional misfire on acceleration. I just had it tuned and everything was ok. Had it tuned by two guys, first one was terrible and burned my exhaust valve in cylinder 2 and he supposedly replaced them. Second guy did a great job and the car was running fantastically. Decided to mess with launch control on ms2 one time and afterwards the car was running rich and would miss occasionally when accelerating. Here is the borescope of cylinder 2. All cylinder are within spec of each other compression wise.

I tested the injectors hoping one was bad they were all ok. Also unplugged my water/meth injection in hopes it was leaking or something. Drove it for a like 5 miles and the misfire was gone but when I parked it and looked in the cylinder it’s still damp looking in there and the plug was black. It’s only cylinder two though.










Can someone point me in the right direction?

 

My screens a little washed out from the sun, but it appears to be some signs of detonation in those photos, typical of a little too much advance, or extremely high cylinder temps, typical of supercharged setups. Post your current tune and a datalog if you've got it, I'm guessing it's a bit spicy without a lot of MAT retard.