my arosa 1.4 8v MPI is running like *****, its hunting. reving from 1000 - 2000rpm, found a burst vacume hose, replaced it only for it to drop to about 1500rpm, but i still have the problem with the hunting. any ideas? when im driving, it kinna chuggs. ma mate says it will take the engine management a wee while to fix its self. when i rev the car, it take a good 5 seconds for the revs to drop.