I have a 1993 Chevy Lumina V6. The Speedometer does not work. In addition, the it doesn't sound like it ever shifts. It runs the same in Overdrive or Drive. From a stop, you have to floor it to get going. It burns fuel like no tomorrow. It has had a tuneup. the other day, all of a sudden, on the Highway, the speedometer kicked in, and it started running beautifully. Shifting, stayed running when you started it, was getting great fuel economy. Then, just as suddenly as it started working, it stopped. So for almost 2 weeks, it would randomly work then quit. What could be the problem? I want to fix it, because let me tell you, when it kicks on, it is like an entirely different car, shifting, running smooth and not loud, and gets great fuel economy (for a Lumina). So please guide me here...
