Crazy Speedo
 

ok here goes. I have a 91 XJ manual tranny, have replaced the speed sensor 3 times, they just don't seem to last very long. the problem is, that everything will be working great for a month or so then all of a sudden I will see the speedo needle flicker up and down...real fast and then stop and be normal again. I see it when I hit a bad bump also, and today, sitting still, when I would rev up the motor, the speedo would go nuts, flicking up to 85 and almost max when I started driving, after a few min, it stopped and all was normal again....could this be the sensor ??? again ??? IF it is a wiring problem when would I look ? thanks for any advice some one would give...

Where are you getting the sensors from? You may want to see if you can find an OEM one. A lot of after market sensors are garbage and rarely work,

This exact thing happened with my 01. My OSU wiring was touching each other and grounding off. I would check sensor wiring al over the engine bay

Thanks guys for the replies, well I have been getting the VSS from E-Bay, after market...I did order a OEM sensor, so we'll see if that helps...i hope so. I am tired of changing them. as far as checking the wires, everything looks good, but you got me thinking about the plug on the sensor, maybe I better check the pins, maybe one of them is spred and not making a good contact or something. you mentioned the OSU, what is that ? thanks again for the input.

The OSU as in the oil pressure sending unit sensor