scikoticEGhatch

So i have a 92 EG hatch with a 95 b18c gsr motor, its got a comptech air box, aem high flow fuel rail and a bigger throttle body and a knock off skunk 2 intake mani i think, but anyways i was driving earlier and i was in 2nd gear goin 20 mph and then it started to kinda jerk forward an back even tho my foot was still in the same position as it was at a steady 20. Then i shut it off ans got back into my car and started down the road and did it again so i pulled over and then it went below 1k rpm, more like 500 rpm and almost died, an now when im at a stop it will rev up to 2k rpm and then back down to 1000 then up to 1500 and just bounce from bout 1100-1400 rpm... Question is it a vacuum leak by chance? Or my fuel rail? Which i highly doubt, i just bought new ngk iridium spark plugs and will install them tomorrow but what do you guys think??