sticky tachometer, sticks at 2000 rpm's Options

[ice cold]

The tach on my 76 2.0 liter likes to stop at 2000 rpms when the rpms drop. Blip the throttle and it settles back to the proper rpms. Any ideas about a remedy? Is this a guage problem or a wiring issue?

[bperry]

I had a similar issue about 30 years ago in mine.
In my case it was a warped lens on the gauge.
The original lens in mine was plastic and it was warped concave
and the needle would rub and hit the lens at about 2500 rpm
and get stuck occasionally.
I ended up replacing the plastic lens for a glass one I made at a art glass framing shop.
I had to score the circle on the glass and break the glass myself because the guys at the shop were horrible at math.
It was sad to watch them screw up the size twice before I finally just
got them to let me use their tools to do it.
It was simple you just had to do some simple math
to calculate the radius (like divide the measured diameter by 2).
They kept trying to eye ball it.

The biggest part of the job was removing the ring on the front of the tach
to get the lens out. It requires bending the back side of the retaining ring
all the way around.

The way you can tell if the lens is warped/bowed is to look at the reflection
and check for distortions.
In my case when I looked at it I could see myself magnified.

I still think that is is really odd that the original tach lens was plastic.
The glass I replaced it with was much clearer and still clear to this day
whereas the original lens was a bit foggy after just 10 years back in 1984.

--- bill

[bdstone914]

If it is a warped lend you can get a glass one from a 70-73 tach with the silver center.
Bruce