VTECwalka

94 civic ex D16Z6. Ok so here's the story. For awhile now I have had Idle problems. When i first start my car up the idle is at about 1500 rpm's i drive it down the street and at the stop sign my idle is sitting at 1000 rpm's just like it should. But as i continue driving and the engine warms up the idle will jump between 300 and 800 rpm's to the point where my steering wheel shakes and the car sounds like it's about to shut off. The engine has never actually shut off. But im afraid it will in the future. On that note. As im about to go to a stop my rpm's jump up then go back down right before i stop, everytime. Now im having the problem where ill be driving and keeping a steady speed and the rpm's slightly go up and down untill i speed up a little. Then it goes back to normal. I have cleaned out my IAC, Seemed like it was working after that but soon went back to normal. So far that's about it. Could this be a tranny problem? Sometimes when i go into reverse i hear a "clunk" sound. What is that? Also sometimes it will jerk while switching gears. I do have an automatic tranny. Any suggestions?