I just bought my Aurora in Phoenix in August. It is a 1996 with 39,000 miles on it. When i first bought it all the gauges were fine. But then a couple months went by and then all of a sudden when I am driving down the road in it (doesnt matter what speed) the RPM gauge just starts moving up and down really fast. Does anybody know what is wrong?
I would check the throttle position sensor (as per JimW) Or a leaking pcv valve hose, Idle Control Motor , Egr valve sticking open, Dirty throttle body. fuel pressure regulator leaking Did you have your Aurora scanned?