skipping speedometer

my speedometer on my 94 si sometimes jumps like 20mph faster randomly occasionally? has anyone else had this problem or know how to fix it. The tach is also a lil off i think.

hey man, i just had that problem too, found out my ignition switch went out, they are pretty pricey (200 or so) but you can acutally use a push-pull switch that you can buy from autozone and go into your steering column and wire your ignition and constant to the switch, only downfall is you have to pull the switch before you turn your key, but it saves ya a lot of money on the long run!!