Help pls. Got idle and transmission probs.

[240tek]

Okcouple of problems, any help would be great. I'm going to go out on a limb and say that I stalled my car, on more than a few occasions. However, after I stall and turn the car back on quickly, it revs up and idles at 1800. ?? What's up with that? Another thing is, when I shift quickly from first to second I get a weird rubbing like the transmission isn't fully disengaged. I'd just say that this is simply a cltuch prob but I was told when I bought it that the clutch was fairly new. While I never saw proof, I don't have any real reason to disbelieve that info. I am concerned with this mainly because almost everytime I shift I feel a weird knock in the shift knob when engaging the gear. Usually it's soft, like the gear just didn't want to engage yet. ALSO, Sometimes there's a huge "KNOCK" that sounds like it's coming from the differential or somewhere below the hatch area when I engage or disengage the transmission. It's hard to describe, but the only thing I can liken it to is this: Lets assume that my differential or transmission is completely loose. When I push or let out the clutch it bangs or knocks. It's as if, assuming the diff or transmission is loose, that the diff or the transmission is being torqued up when I gas it, out of its proper seat, and when I push the clutch in it drops back down and bangs/knocks. Sorry, but that's the only way I can describe the sound. Any suggestions? Thanks alot. Tek.