2k miles ago I rebuilt my engine (90 Z24). Since then my transmission has been acting weird. First is fine, but when it shifts from first to second it glides in, taking up to a few seconds. And then sometimes it accelerates fine through second and other times it hesitates. It shifts into third fine and then works like a champ again. Untill today... on the way to work this morning, it started working correctly, shifting hard, but only occasionally. Sometimes it would be hard, then medium, then slow again, and then hard again, teasing me. I rebuilt the tranny also about 4k miles ago, so its new as well. Any ideas as to what is causing this or how to fix it? Any help would be great!