i recently installed a new speedometer unit in my 96 v6 accord due to speedometer and odometer issues. after i replaced it they both worked fine but the tach is acting wierd. it still idles about the same but when you get on it the tach moves way too fast . it redlines at around 6 but now goes well into the red like around 8 or 8500. does anyone know why? could it be the speedometer cluster came out of a 4 cyl instead of a 6. thanks for all your help