I tried replacing the speed sensor thinking that would make the speedometer work again. But it didnt. What else could be the problem? It normally doesn't work, but every now and then it'll work or just spaz out and go crazy.

 

I also tried replacing the speed sensor on my 94 coupe 5 speed manual. It didn't fix the problem. It seems to start and stop when I hit bumps in the road or pressed the trip reset button so it must be a connection problem in the speedometer. I took the thing apart, applied die electric grease to the three fine thread machine screws that mount the speedo to the cluster(they also transmit 12v power, ground and a signal from the vehicle speed sensor( vss). Didn't fix the problem. Put the front of the car on jack stands and let the car idle in 5th gear. Pulled the gauge cluster out but left all 4 connectors plugged in. It seemed to start, stop and freak right out (twitch) when I turned one of the mounting screws. The one that completes the ground path actually which I think was the top screw. Still not working. I may try soldering 3 wires from the little circuit board on the back of the speedo directly to wiring harness. We will see if that works.

 

My stock EG cluster used to do this too. Would stop working or the speedo needle would jump to like 120 and then come back down. I ended up getting an Si-R cluster and it hasnt ever had a problem since. So maybe try and get a new cluster and see if it works.

 

Is code 17 thrown?