Try purging the junk out of the lines between the fuel distributor and the fuel injectors by removing the injectors and cranking the engine a little. (Don't let fuel catch on fire though). Also try tapping the injectors on a block of wood so that any junk inside them will come out backwards. I have been thinking that the problem was a clogged fuel filter. I was absolutely convinced of this when I bought the car. But clogged injectors make it act just exactly like a clogged fuel filter, right? This is the same principle. I have two black plugs and two clean plugs. Probably the black plugs come from bad injectors dumping raw gas into the cylinder and these cylinders will therefore lack power bigtime, though not enough to make it seem like a missing cylinder. Although I do get a missing cylinder for 2 minutes when temp is below freezing. It all adds up.
Check out this other thread. I put a double shot of fuel infoector cleaner in one tank and got 5mph improvement on the top end.
low power on acceleration