I started noticing a power loss on my 2.0 ranger engine a few months back and yesterday it hit its worst point basically undriveable. I ran a compression test about a month ago when it was still tolerable to drive and it had 110 on every cylinder except #4 it had 95pounds. I've been noticing a lot of valvetrain noise since worse now than when the power loss started. Today I put a vacuum gauge on it and its fluctuating slightly between 18 and 20 hg timing is at 10 degreesbtdc. I also pulled the plugs and all looked good except #4 was wet I can pull the #4 plug wire and it has no affect on the engine while running also replaced that plug wire with no difference. I would like some advice on what to try next I'm leaning torward the camshaft being wiped on that cylinder due to the valvetrain noise and how wore the followers and cam were when I replaced the valve seals about a year ago.