My '86 IROC's tach won't go to zero when you shut it off. Whatever RPM it was at (idle) it stays at when you turn the car off. BUT...when you turn the ignition on (not starting but the ACC), it will zero. Any thoughts?

 

It's an electronic tach. They do that.

 

so...no quick way to fix? just live with it huh?

 

my auto meter tach does the same.. it is not broken.. so it does not need to be fixed

edit... if it really pisses you off. you can shut the car off to the accesories position for a 1/4 second b4 shutting all the way down and it should 0 out

 

Yea, but as soon as he slams the door it'll pop back up!

Try tapping on the dial faces or the dash above the dials...see how high you can get the needle! I got mine to 4,500 before I got bored.

Si

 

like everyone said its just the way of life. it really bothers you that bad?

 

mine does that too, it's normal

 

Hellno it doesn't bother me that bad! i was just wondering why it did that and if there was a quick fix. don't worry, i won't be in bed tonight dreaming about killer tachs that won't zero coming after me. :lala:

 

What you gotta realize is, when the car's off, the RPMs are actually, in fact, at zero, regardless of the tach reading. Therefore, these guages are highly inaccurate, stating that the engine is running when in fact it's sitting still... it must be fixed!

Hehe, just messin'

 

all it means is when you turn the key off, you kill the tach before the engine comes to a complete stop. therefor the tach reads the last rpm before it was turned off

 

These are the stock tachs? Here is a fix. Get a autometer tach.

 

so, just curious and bored, if it was 1986 and I bought this brand new IROC, the tach would do this even new? Is this true, or is it just something that happens over age?

 

My aftermarket Autometer tach does not do that. Must be a GM thing. That would iritate me too, but anything that does not work iritates me.

 

Why in the hell do you care what your tach reads while the engine isnt running?

 

I have a 2001 Monte Carlo and when the key is off the gas gage reads E does that mean Im out of gas my 84 Trans Am say 3/4 and I just filled both of them up. Im just saying some gages zero out and some dont.

 

I have a 2001 Monte Carlo and when the key is off the gas gage reads E does that mean Im out of gas my 84 Trans Am say 3/4 and I just filled both of them up. Im just saying some gages zero out and some dont.

 

..

 

excuse the hell outa me!

 

Its normal. Its like the guages on newer gm cars will max out when you cstart the car to calibrate themselves or something, then read the correct readings.

If the tach pegged when you started the car like my 87 camaro did, then you have a problem. I fixed that easily ... with a swift punch to the dash! And the amazing part was that it worked after that. No lie ...
~Tim

 

mine did that too no biggie, before the motor blew today

 

Thats how I get my Volt gauge to work..

 

I do the same to my Nissan pickup every day.