Tach needle sticks randomly

[ramonesfreak]

The past 2 days I have noticed that when I come to a stop, the tach needle sometimes stops at 1,400 RPM. If I blip the throttle it will return to 950. I cant reproduce it. In fact I just drove around the neighborhood with lots of stop signs for an hour trying to and couldn't--- but it has done it 4 times today and a handful yesterday. b

Never seen it do this in 17 years.

Timing is to spec. Just checked. Car runs good. Idle is always perfect no matter what the temperature. Tach does not bounce around...no surging, no stalling nothing else weird.

My shop last week installed a new distributor green 'pigtail' green wire.

I did install a new cruise control cable last weekend....maybe that could be hanging ever so slightly randomly...it looks to be at the right tension though...but this is the only thing I can think of

Its not just the needle getting stuck, I can hear the engine is idling higher when it happens

Ive looked at all the other idle and tach threads and havent found anything

Any thoughts on where to start looking besides a closer inspection of the cruise control cable?

[GH85Carrera]

You say the tach sticks, I presume that means the engine RPM is that high as well, so it is not just a bad tach.

I would temporarily remove the cruise cable for a while, and see if it happens again. That would tell you for sure, it is the cable. I love my cruise control on road trips, and it should not interfere of course.

[ramonesfreak]

correct. not a sticky needle.

dang it though - i was a responsible mechanic and lock-tited those nuts that hold the CC bracket on :-(

[ramonesfreak]

confirmed it is not the CC cable. it stuck at 1250 about 4 miles into my drive from a cold start.

pulled over with it stuck and checked throttle linkage and CC and all good. blipped a few times. did not come down.

continued on for over an hour on highway, city streets, various speeds and stop and go and couldn’t reproduce it again.

so, something suddenly after all these years is causing it to hang. whether this related to temp not sure yet. will continue to drive and do experiments and read.