1983 Camaro Berlinetta, V6...tachometer

[vzfox]

My tach always reads "max'd out"....doesnt matter if the car is running or not. Every once in a while it will go down to 6000rpm, but then goes right back up to 7000rpm (which is the max).

Any ideas on what could be causing this?

[Morley]

Originally Posted by vzfox

My tach always reads "max'd out"....doesnt matter if the car is running or not. Every once in a while it will go down to 6000rpm, but then goes right back up to 7000rpm (which is the max).

Any ideas on what could be causing this?

Old tired tach. All third gens have tachs that read high or are going to very soon. And once they start reading high it just keeps getting worse and worse.

[vzfox]

Originally Posted by Morley

Old tired tach. All third gens have tachs that read high or are going to very soon. And once they start reading high it just keeps getting worse and worse.

Do you know of any websites I can go to that sell rebuilt or new tach's that will fit "factory" in my '83 Camaro?

Are there any tests I can run on the wiring or existing tach to determine that it is indeed "worn out"?

[Morley]

The cheapest and easiest "check" would be to replace the ignition coil and see if that is the problem. Other than that you could look in junkyards and on E Bay for a replacement.

[vzfox]

I hate to sound ignorant....but if the ignition coil was bad, wouldnt it affect more than just the tach? Like, not starting and such?

[vzfox]

By using a jumper wire and going from the red (battery) wire to the yellow (tachometer) wire on the ignition coil, I was able to make the tach fall back down to zero.

Using a ohm meter, I measured across the black (tachometer) wire on the coil to the distributor spark plug wire on the coil. The book says it should read very high, but not infinate.....it reads infinate (ohm meter on high setting) and reads zero (ohm meter set on low setting).

Is my ignition coil bad? (all tests were done with coil wires unplugged from coil).

P.S. the car will start and run good (all wires plugged back in of course) but tach reads 7000rpm all the time.

This is the older seperate-from-distributor type coil, mounted on passenger side valve cover.

[Morley]

Sounds like your coil may be T.U. But you won't really know for sure if that is the problem until you try replacing the coil. They can be had fairly cheap and then you'll have a spare. When a coil goes out (ignition side) it gives no warning, just kaputt.
For the poster above...The tach signal can be bad and and the coil still be able to run the car.

[vzfox]

Well....I went out and bought a new ignition coil, installed it and cranked up the car. Back up to 7000rpm and stays, running or not. But if the idle begins to drop, like the car is going to die, the tach will then begin to back off/drop down by a couple thousand rpm's.

I also tried pulling/tugging on the wires that connect to the ignition coil, and nothing happened, the tach didnt change. I still dont think the tachometer itself is bad, but rather something making it read incorrectly.

Thoughts and ideas, pleaseeeeeeeee......

[hotrod_chevyz]

Mine is the same way. Its simply a bad tach, nothing more. Just mount another one cause the chances of finding a good used ones are slim to none.

[vzfox]

Your probably right on the used tach deal.....tell me how to post pictures like you (hotrod) did, and I'll try to take some and post them here as well.

One more question......if I just simply leave the tachometer alone for now, with it showing 7000rpms, will it affect the way it idles or runs?

[hotrod_chevyz]

Start a free account with "photobucket dot com" and upload some pics, copy and paste the "IMG code" into your post and click post reply. once you start an account you will see what i mean by "IMG code".

EDIT: no it will not affect how it runs. If you rev into the motor too high you could blow something up because you dont know what rpm's your running it at. Most people naturally pull out of the throttle before they redline so just watch how hard you run it. If your like a normal individual you have nothing to worry about on it but if your like me, and some of the other knuckle-heads on this site, a tach is a good piece of hardware to have. It keeps your rods on the inside of the motor.