1 dead cylinder & no brakes

[rosso75]

I'm helping a friend with his '93 MX-3 (1.6, AT) and we've got a couple problems. First, we've got a dead cylinder. The plug is completely black and the car runs rough at idle. The other plugs are fine (all are new), and the car actually seems to run fine at higher rpm's. I swaped the plug wires around to see if maybe a wire was bad, but the same plug still fouls. I'm thinking maybe an injector?
Also, the brake pedal is real firm with no real braking action. Should I be looking for a vacuum leak from the booster, or maybe the booster itself?
Thanks
Bryan

[Yoda]

Is it the #1 cylinder? For whatever reason it is common on the (16V) SOHC to loose compression and leak oil into the cylinder for some reason. I've pulled apart 2 of these heads. There was a heavy deposit of "coked" oil on the top of the piston, the rings didn't seal and looked like a chunk of carbon went through the valves damaging the seat. it must have bent the valve stem because oil was seaping down the valve stem. I remember about 4 years ago a friend that own a garage had 23 regular customers with SOHC MX-3 back them about 78% of them were down 20-30psi on the #1 cylinder.

[rosso75]

It's the #4 cylinder. Strange thing though - I pulled the fuel rail and swapped the #1 and #4 injectors. If it was the injector, the problem would move from #4 cylinder to #1, right? Turns out the problem just went away. I'm guessing there was a loose connection between the injector and the plug. Sometimes the little things kill you, 'eh? Also cleared up the brake problem, and that one I'll never understand. Must have been an air leak somewhere, and somehow it got sealed.
Bryan