I have a '96 Geo Tracker with 110K miles on it. It was running pretty well until I had to get the water pump replaced. Well, now I have a new water pump, but there's a new problem now; my car don't run so smoothly. It vibrates pretty badly, both with and without the gas pedal pushed. Also, because of the vibration, can't climb into high RPMs real well, so now it drives slowly. Another thing is that if driven hard, smoke blows out the engine. Does anybody have any idea what could be causing this problem? Any help or hints would be appreciated.