I've started my R33 GTR today and found out that my tacho was doing strange things. When the engine is idling, it works ok and shows the real rev value. But when I rev the engine a little bit, if it goes higher than 1,800rpm (approx), it begins working backways!!! The more you rev the engine, the closer you get to 0rpm!!
After a given rpm value, the needle is even stuck on 0rpm and is not moving anymore.
If you back off the throttle and let the engine slow down until iddle, the needle comes back to life and shows true rev value again (1,000 rpm).
And so on.
any ideas how to fix this? it started after i pulled the cluster out to change globes, have checked all connections and cleaned them. no avail.
ive read it may be a loose earth wire,