this is what my tach is doing, any idea why its so far off?
red lines way early, shows low idle.

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Could be caused by a poor tach signal, which you could jumper the Black Bullet connectors at both coils together and this will cause the leading coil to provide a tach signal rather than the trailing coil. The Yellow/Blue wire at the trailing coil normally provides the signal. It could also be a loose connection/dirty plug. Try this as it is the easiest test to do. It could also be a loose connection/dirty plug. It could also be the tach needs recalibration which requires the removal of the instrument cluster or it could be the tach itself or something related to the ECU. The

 

ive tried 3 different coils, and all have same results, calibrating the tach... hmm how lol?

 

You'll have to do a search. Try the jumper technique as it takes all of a minute to do. If the wiring from the coil to tach is poor then a different trailing coil isn't going to help.

 

I have another s4 cluster, difference is this one is the 160mph one, should be fine i think right?

 

I would not know.

And one minute of searching found this.

https://www.rx7club.com/showthread.p...ch+calibration

 

Hm, All i found was 'tach calibration for v6 and v8'

 

Other than no oil pressure.............just what am I supposed to be seeing that is unusual? I've no idea what gear your in so I can't say what the tach should be reading.

Get in fifth gear and drive at a steady sixty mph and tell us what the tach reads and then do the same at 70mph.

What year car? Model?

 

car idles below 0, and redlines (audio is there) well before redline. gauge cluster shows that said car is n/a and a s4...

anyhow ive got another cluster im putting in, all the gauges seem ok and ive cleaned it up.

 

My car does the same thing!
I grounded all coils to the Frame and the negative Post of the battery,still the same Bouncing.
I have yet to try the bullet connector thing as I am "cheap".haha!