RPM-meter varies

jandav

My RPM meter varies when the engine are running on a fixed rpm.
What can I do to fix this?

Thanks in advance
Jan Davidsson
Kungälv, Sweden

LaRea

It's a common problem with the Faria tachs.  Try re-seating the plug on the back of the meter, and checking for loose ground wires.

Handymans342

Hit it with fist

Willhound

Handymans342 said:

Hit it with fist

That's my fix. 

Liberty44140

X3, I tap the tacks lightly with my iPhone and all is good 

Lake_Bum

Mine did that all last season, I checked all ground wires, did the tap method, nothing worked.  I would say about 75% of the time the tach seems to be correct, the other part it shows to be redlining so I just decided to leave it.  Doesn't bother me too bad 

raybo3

Here is what I do....... I take the dash apart and on the back of the tach's is a "pot". I look at where the pot is and then I take a small screw driver and I turn the pot clock and counter clock wise about 6 or 7 times and then put it back where it was and all is good for about 2 years................... Just say'n

Wildboating

Install a vessel view digital gauge that reads directly from the engine ECM.  Several have done it, type vessel view in the search bar.

jandav

Thanks for all input!
I will come back with feedback.

andyd

I call mine a tapometer. I'm going to try raybo3's potentiometer tip. Thanks!

Andy

randy56

The first time it happened on my 270, my wife was driving, about 1800 rpm's nice and easy, I was enjoying a refreshing beverage, and the tack  jumped to 4000 rpm's,  thump O meter. 

Willhound

Yeah. Now that I'm at the start of my second season with over 100 hours under my belt I trust my ears. Not the tach. Still wack it from time to time though .