My 95 Civic EX Coupe Auto recently started surging while idling. It suddenly goes from about 500 rpm to about 1,000 rpm for no reason at all. It's cycling like that every 4-5 seconds. There's no check engine light, and I don't know how to check for codes. Anyone have an idea where to start looking? Also, could it be related to flat spots on acceleration? Car is 100% stock, and it runs excellent, otherwise. Please be specific in your answers, since I'm new to Hondas. Thanks to all in advance.