lately my 84 Jimmy has been having some problems with the throttle. it started when it started getting cold here in IL, and it was like the throttle was getting stuck open. i have a manual, so i can manage it OK but when i would just be stopped at a light or anytime i would put in the clutch, it revs way up to near 2000 rpm's and stays there. i have tried really punching the gas to see if it will let loose but that doesnt seem to do it. then lately it has been doing something else. either it is reving way high like that, or it is like it is not idling high enough, so when i am in low rpms, and accelerating it is like it is not getting enough gas so it will jerk real hard on me, like it is going to choke and die right there, it never does, i just back off a little, and it catches up, but i dont get it. so it has been doing on of those two things almost everytime i drive it. and it is really spiratic. i never know what it will do. one time when it was reving at 2000 rpms, i stopped and left it running and pulled of my air filter to just see what wsa going on, and i saw underneath there, ther is a little lever to the left of the carb. and when i would push that a little, then it would click to a different position, and the rpms woiuld be normal. i dont know what i was doing or anything i am not a mechanic, but i am trying to learn, and do as much of this stuff myself as i can. so any advice would be greatly appreciated,i want to try to get it taken care of before i head back to school in a week. thanks for any advice.