Speedometer Issues!

[silverkaturbo]

I have a 91 240sx se with the normal analog speedometer and the needle is usually running about 5mph over or under my actual speed. Sometimes it will jump back and forth, sometimes it will just sit at zero, but very rarely will it give me a accurate reading. A couple times I have smacked my dash and it returned to normal, but that hardly ever works. So do you guys think it is a short or could it be as simple as replacing the sensor? All other gauges work fine.

[MRNA]

Most of them do that, analog and HUD. Pull the display and check all the connections with a multimeter. If they all work get an OEM replacement gauge.