Jumpy Tach

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D See 2

Senior Member
what could cause a tachometer (both aftermarket and stock) to be jumpy. its very erratic. it didnt always do this. just started a couple of months ago. could a faulty distributor igniter cause this.


Senior Member
uhh erratic Tach could be your clutch is all done bro :)

the clutch slips all the time, and makes the revs fluctuate, even maybe not audibly. Usually this is easy to notice because of engine noise. It all depends on how erratic and when


Senior Member
my buddys 89 tegra had the same problem we had to replace the a senor wthin the distributor which was causing a poor spark and the altinator was also bad

90 accord

Chicks dig the box
i'm assuming that your engine does not rev up with the tach?

i had a similar thing happen to me, took it to a dealership,and they said the wires that attach to the coil were comming off. they re soldered them and it works fine now
Is you ecu showing any codes? This idle jumping up and down like that is one of several things to check. The IAC valve, perform a vaccum check,.

D See 2

Senior Member
its not my idle or motor...JUST the tach. the engine itself does NOT fluctuate in idle.


Senior Member
my crx did that when i first bought

my tach was moody didnt wanna work when i wanted it too

i always caught it working when i could really careless if it did

:angry: litte bastard :angry:

i replaced the clutch(becuase it was shot) and it works like a champ now

i agree with liquid00meth


Junior Member
It could be your coil wires. Sometimes when there is bad connections between them, the RPMs will fluctuate that way, only on the needles. Check for old or corroded wires or just bad connections in your wires.


Super Moderator
With the aftermarket tach, are you running right off the ECU? I would also try to use a multimeter and check the RPMs that way. It could also be a short some where. Is it all the time or just at Idel? How much does it bounce?