So I was playing around with my s300 program and I found an option for a shift light. I set it to flash at 7800 rpm as my check engine light. My redline is about 8200. It hasn't seemed to work though. Hasnt flashed once. I did notice at high rpm the rpm needle starts sporatically jumping around. Any one know what this could be as well?

 

stock tachs are not accurate at all. when the engine is at 7800, the tach will actually read 8k-8300. try setting the shift light to like 6500 just to make sure it's actually working

 

Ok I will try this tonight. Where can I get a good tach?

 

If you want an accurate tach buy a "Stack" unit!
proven in many winning race cars around the globe.
We also use them in our cars.

 

Where can I find these and how much?

 

http://www.stackltd.com/us_dists.html
there u can find dealer for the US Market.
i dont know the prices in the us but in europe its about 450$ for the clubman unit from 0-10000rpm

 

autometer tachs are perfectly fine.

 

What year/make/model is the vehicle your tach is going nuts on?

 

Its a 95 integra ls with a n/a b20vtec

 

have you tried this yet?

also, the bouncy tach thing could be a bad or loose or dirty ground.

 

I let my buddy borrow my ecu usb connecting cord after we did the shift light. I will do it as soon as I get it back and let you know what happens! Also going to check my grounds now