I have a very strange problem with my RPM gauge, that i have never experienced before on any car. And i cant figure out what it is.
Searching the forum, and reading throught the fd3s.net troubleshooting guides didnt give me anything on the problem, so then i am asking here.

The problem is, that the RPM gauge is crazy.
When driving on the highway, in about 60mph, the needle can suddently drop 1k rpm and then function like normal, on this RPM. Its hard to notice since i cant drive with my eyes on the gauge, but when cruising at stable speed, i can suddently see the needle moving a lot.

Also, when i started the car today, the needle went straight to 9k rpm, stayed there for 2 sec, then dropped down to idle rpm. I was not able to reproduce the behaciour, and the needle appear to work when revving the engine.

And last, sometimes the needle is "sticky", meaning it will not move smooth on acceleration, but jump 500-1000rpm, then move normal, then jump again.


All the problems happend pretty random, and i am not able to reproduce them when revving, or when accelerating. It just happends from time to time, and more often lately. There are no mods on the car, and everything in the electrical system is 100% bone stock.

 

http://www.wrex-racing.com/docs/fd/Tach_Repair.pdf

 

Thanks a lot! Would never have found this on my own

 

I have the same problem. thanks for the post and fix