Just did a compression test... 7 of my cylinders are at 160psi to 165psi (seems almost too uniform... probably going to retest tomorrow just to be certain). My number 3 cylinder, however, came out at 185psi. I've read that this could be the result of carbon build-up, but haven't been able to find any causes or solutions.

Injectors, plugs, and wires are all new. What kind of valve issues could cause this? As far as cleaning, would spraying carb-cleaner or another solvent directly into the cylinder (via the spark plug) be effective or dangerous?

Seafoam works excellent for removing carbon buildup. You can buy it at Napa, Walmart, etc... You can put it in the gas tank or directly into the brake booster vacuum hose for carbon removal, or in the crankcase for engine sludge. They also make a spray called Deep Creep for cleaning the throttle body/induction system. Just follow directions on the can. Also somewhere on here there is a very detailed procedure on this. Maybe do a seach? Hope this helps Dave.

Yea don't use carb cleaner, it can foul the O2's, MAF cleaner or throttle body cleaner would be safer.

165 & 185 are almost within 10% of each other. Retest it after it has sat and hold the TB wide open during the cranking. Carbon build up would be unusual in a late model car UNLESS you have some oil seepage into the cylinder and it's getting burnt.

I did a compression test on an old Suzuki LT230 years ago and it had 230 psi of compression. Pulled the head off and there was oil pooled on top of the piston and was sealing it up. It was worn out.