At 10:06 PM 2/13/2002 -0500, you wrote: >. I have found heavy carbon on plugs on cylinders 2 and 8 on the right side. Is it possible that your mixture is too rich and it fouls those plugs? Then of course, why just those two plugs and not the others? Is it possible that the valve guides in these two cylinders are shot? You said your compression is good, so the rings must be OK. If you clean the plugs and re-install them, does it run right for a while, and then starts missing? You said you have new plug wires, but is it possible for one or more of those to be defective? Have you tried the "darkness test"? Let the engine run in the dark and look for sparks under the hood, especially when the engine is missing. If you see any, you have bad plug wires. Its possible for the spark to "leak" only under load because the electrical resistance of the plug gap increases with load, and the spark will try to find the path of least resistance which might not be through the plug gap if the wires are no good. D^2