GSRcivicSon

alright so my car has been acting up a bit, and im not the best with diagnosing stuff like this so im hoping to get some help on here. main issues are while the car is at full operating temp and just sitting my idle with be around 2k, and then if sitting for long enough it will start to drop and then raise back up, and just bounce down and up. also while driving when i let off the gas to just coast the car will jerk a bit and sometimes feel like it wants to stall out. and lastly if i beat on it and get into high rpms i get a burning smell? not sure if its fuel or what. i know all this isnt the best description but i just need to atleast figure out where to start. any help would be much appreciated. oh yeah, car is a 99 civic ex with a jdm b18c1 with bolts and a phearable.net chipped ecu.