Weird Loping Idle

[pacotaco345]

Okay so this doesn't happen every time I drive the car but it does happen occasionally, usually when its warm out. I have a 91 kade auto, and when idling (w/foot either off brake or very light pressure) the car will jump forward and slow down repeatedly, usually traveling 3-4 feet in its lurches. If anyone has driven a manual car with an aluminum flywheel, it feels like those low rpm bucking bronco surges that occur when you don't engage the clutch smoothly. If anyone has any suggestions before I rear end someone it would be great.