Strange Speedometer problem

[DammitBobby]

91 240sx Manual 5 speed.Occasionally when driving my speedometer will bounce from what speed I am driving to 20 or 30 mph faster then what I am driving. It just started doing this a few weeks ago. I am wondering if somebody else has had this problem and what do I need to do to fix it. Also If I have to take the cluster gauges out I want to put in reverse gauges. Has anybody done this and where to get them.Thanks.

[ELITEBB127108]

i have the same problem....mine is worse though.....it would go alll the way down to where the milage is....i think you would have to replace the speed sensor on the transmission.....or it could be the cluster....not too sure...

[DammitBobby]

Hmm is the Speedometer electronic or does it have a cable?

[[Zero-S]]

Electronic. Only cable driven speedo I've seen was in my friends RB20...old skewel what.

[240dreamer]

vehicle speed sensor most likely...is your engine throwing a code?

-Adam

[DammitBobby]

How can I tell I am getting an error code?