Hmmm, kind of hard to diagnose like that. I would try to replace the stock linkage with a quadrant kit which will include a new quadrant, cable, and some have a firewall adjuster as well. The stock linkage is a gremlin waiting to get irritated. Even if it doesn't fix it, it will have eliminated the worse part of the clutch system, and you will be able to dianose it a lot better.