Alright so I just got my FD and it has a few minor issues that im working on but this one is bugging me the most. Sometimes my Tach will work perfectly, but when i go to work in the morning (colder temps maybe?) it may read funny like at 4k when im idling at 970 or at 4-7k while im driving. Then next time I start it it may work perfectly or glitch for a bit still. My Power FC shows me the engine revs now and a aftermarket tach from the previous owner that i desperatly want to get rid of. Anyone ideas of what the problem is?

 

I'm afraid you will need to remove it and check for bad components. The inconsistent reading is indicitive of failing components.

 

yeah i was thinking of tearing into it this weekend. Bit upset cause Ive been looking and a replacement stock tach would cost alot if the tach itself is messed up