just kidding about the driving fast part. But, on returning from a DE this past weekend, my speedo needle started bouncing around. First it was bouncing around within a 5 mph range and then it was bouncing around from 45 to 65 mph (when I was driving about 65). Any ideas what is failing and what the repair involves? Is the problem likely in the speedo gauge itself or someplace else (Cable, gear, sensor, etc)?

 

Sounds like a sticky drive cable .

 

Speedo is driven by an electrical pulse signal - you could try cleaning the electrical connection to the pickup sensor.

You'll have to figure out (do a rennlist search?) where that sensor is, on my '90 C2 it is on the right side of the transmission but I seem to recall that some of the later cars pulled the signal from one of the ABS sensors instead...

 

the speedo is driven of of the ABS wheel speed sensor - is your ABS working?
it might be a relay, the computer, the speedo, etc.

(btw, when you disable ABS via the kill switch in my car the speedo and the Odo stop working as well)

 

Hahah...

Cop: "Sir, do you have any idea how fast you were going?"
Cupcar#12: "No idea Officer, my speedo is disconnected"

 

My Lotus Elise used to do that while I was stationary at the lights. Suddenly it would shoot around to the far side of 100 for a few seconds.

Mind you, that's Lotus for you, isn't it?

 

then i ask him to pull up on the lever on the cowl - turning the whole car off and claim it's broken