95 galant s rpm tach
 

Ok i was driving down 75 south and i was goin 55 and my rpm tach starting to jump from 2,500 rpm to 3k then back down to 2,500. I checked my vacuum tubes and my throttle cable and everything seemed fine. I think it could possibly be the sensor is bad or the wiring is wrong. Im not really sure. I have a 1995 Mitsubishi Galant S, its a 5 speed. If anybody could possibly trouble shoot the problem for me it would be great.