I noticed the other day that was in a while my car doesn't idle completely smooth. It runs great and as plenty of power but something just doesnt seem right. It normally idles at about 850 rpms but sometimes it will drop down to about 650-700 or shoot up to about 1100 for just a brief second. I also noticed last night that when it does it, it seems i get a small power surge, and sometimes when i look at my battery gauge it's a little high, not right in the middle where it should be. I don't think its a mis-fire, im thinking i might just have a problem with my alternator? Or maybe i just need a tune-up?