I can see fuel pressure causing random misfires or misfires on all cylinders, but 1 cyl? We are not even sure it really is a misfire at this point. We need to do more diagnosis. Would a weak valve spring cause this? At an idle, there is misfires, but slow count. Above 1700 rpms the count just flies. The O2 sensor doesn't look like it's going lean, but it has a lean rattle. When we resealed the lower intake manifold, the distributor did not appear bad. The brand new distributor cap was replaced with another brand new one and didn't change symptoms.