Factory tach is way off, how to fix?

[N2O_ZX2]

My factory gauge cluster has some wierd issues with the tach. When its sitting at idle, the tach says between 100-200rpms. And, when you rev it up to around 4k it sounds like its running WAY faster. My question is, what do i have to replace to get the thing accurate? Could I switch out to another cluster or is it a wiring/electrical problem? How is the tach read? Im assuming its through the ECU, but im new to this thing. Thanks.

N2O_ZX2

 

[SexperT]

You prob have a 90 ECU, the 90 ECU will send different signals to the cluster.

 

[N2O_ZX2]

Nope, I already changed that. I appreciate you tryin to help me out tho. The car had one ECU in it when i bought it, and after the idle was all messed up, and it was having problems reving, so I replaced it with a 91 Laser turbo ECU.

N2O_ZX2

 

[SexperT]

just get one from the junkyard, they are all over the place.

 

[N2O_ZX2]

so you think that'd fix it? I can get one pretty easily, i was just wondering if it would be in the cluster or some where else. Thanks

N2O_ZX2

 

[N2O_ZX2]

I threw a new cluster into the car today, and it fixed the tach problem, and the oil pressure gauge works too now. Thanks guys.

N2O_ZX2