Tach is spazing out.

[S14DB]

I start my car to go into work today and the tach goes past 8k and slams into the time set shaft. I disconnected the battery and let it sit for a while. When I put the ignition into the ON position it spaz's out and twitches all over the place. when I start the car it goes up to 8k and hovers there. The rest of the cluster works fine and the car drives fine. It's just that the tach hovers between 7~8K as I drive regardless of engine RPM. I does bounce like crazy over bumps but then slowly goes back to ~8k.

I haven't changed anything in this car in a month and that time it was the oil. WTF is wrong with this thing? Wire, cluster, tach? '98 with ~75k miles.


Edit: http://www.s14db.com/TachFreak.avi

[statik]

The only time ive seen the tach freak out like that was when a.) a CAS goes, b.) wirring issue. c.) bad cluster

a and b usually mean the car will run very badly, example: a wire in my harness grounded itself out on my intake manifold, caused the car to break up BADLY and the tach to jump around like crazy. If this happens before the car is running and the car runs ok imma bet the cluster is the problem, try out a friends =]

[Agamemnon]

Same thing happened to me. I purchased a new cluster off ebay for $30 and swapped tachometers and everything has been working just fine.

[ask52]

This may sound dumb but my tack did the same thing. It turned out to be a bad ground. Engine to chasis.

[S14DB]

Disco Tach:
http://www.s14db.com/TachFreak.avi

Car runs fine. BTW.

[theicecreamdan]

my last s14 was doing that too, I got rid of the car though. I was planning on replacing the cluster though.

[S14DB]

my last s14 was doing that too, I got rid of the car though. I was planning on replacing the cluster though.
Wow, thanks for the help... :p

[evilimport]

Mine does the same thing ever so often, only it goes to around 3-4 grand then settles into place where its supposed to be. Freaked me out the first time I saw it, though.

[!Zar!]

I never had the time to pry into the cluster but my bimmer was doing the exact same thing and the culprit was a battery they used on the cluster was going out.

[S14DB]

Today it goes between random bouncing and being 3k higher than it should and back. I have a Optima red top battery that is less than 6months old. The rest of the cluster works fine. Everything lites up. Nothing changes when I turn on the AC and/or headlights.

[statik]

have you tried out a new cluster yet? that would rule out a big possiblity

[S14DB]

have you tried out a new cluster yet? that would rule out a big possibility
No, cause S14 Kouki clusters are hard to come by.

[theicecreamdan]

I am the teck god, you are so welcome for me helping you.

[S14DB]

I swear I'm going to rip this out with a crowbar!

[www.ka-t.org]

Break Shit!

[240mph]

This problem seems to be a common problem for the 97~98 for some reason.
I also changed out the cluster and worked fine after that.