my tach does not read correctly, it starts out about 5k and quickly pegs. the PO told me it slowly got worse over the years he had the car and that the tach filter was going bad but he never changed it. i want to change it but need to know where it is at, how to change it, and where to get one. thanks in advance.

It looks like this



It is located here


and you can get one here

http://rodneydickman.com/ca...h=21&products_id=165

[This message has been edited by phonedawgz (edited 12-18-2011).]

thanks for the great response which was perfect, i just ordered it, wonder why the one at fiero store is 29.95.

is it easy to remove the stock filter, meaning do you just disconnect it and plug in the new one?

[This message has been edited by 88GTTTOP (edited 12-18-2011).]

1. Stores are allowed to charge what they think the can get for a product.

2. Yep

The only remedy for a tach reading "too high" that I've found is a new tach ! I've taken out & replaced the tach filters in both my 4 cyl car and my 6 cyl car, Makes no difference whatsoever if the tach filter is even installed or not !

The tach filter is there to filter out noise from the ignition. It prevents most of the spikes and spurious stuff from getting to the tach... you can bypass it but the garbage in the signal can lead to inaccuracies or failures in the tach. If it fails, you have a dead tach.

Having a working one is better than not having one at all.

But as lou said... I don't think, from your description of the problem, a filter is going to fix it.

[This message has been edited by carbon (edited 12-19-2011).]

its funny cause i read this post with the EXACT same problem and i just replaced the tach filter today and yep no fix in the high tachometer reading.. The two above me are exactly correct. Now is there anyway i can fix the tachometer that i have or do i really need to get a new one? what is the problem causing the tach to read 3000rpms at idle and get worse over time?

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1988 Pontiac Fiero Gt (has every option available from that year including factory leather, 5-speed, and the rare T-Tops: Black w/ gray interior and blk wheels)
1992 GMC Typhoon #0203
1971Chevorlet Corvette 454cu/ LS5/ 4-speed/ convertible
1993 BMW 850 Ci 6-speed V-12

I had this problem but the tac was also jumping. Turns out after looking at the engine in the dark I had a light show going on. One of the arcing wires was to the tac filter wires. My tac reads right now that I have rerouted wires and eliminated the arcing.

yea that sounds about right but im pretty sure that this is the tachometer itself causing the problem.. btw not trying to hijack this thread...i figure he has the same problem so solutions are the same

i replaced the tach filter today and still have the same problem so i guess i need a new tach for my 88gt. here is a pic of the tach i need to replace. i want one in nice condition, i will post a thread in the mall too.

this pic shows idle when warm.

My 88GT tach had the same symptoms...

And this corrected it

http://www.fieros.de/en/articles/tach.html

The information you need is under Modifying the tach

I did not use a variable resistor instead I opted to make a fixed 280k resistor pack out of 3 resistors I had on hand

It worked great - Many thanks to Oliver Scholz for his Fiero knowledge

Hope this helps,
Pappy

[This message has been edited by Pappy (edited 12-21-2011).]

quote Originally posted by Pappy: My 88GT tach had the same symptoms... And this corrected it http://www.fieros.de/en/articles/tach.html The information you need is under Modifying the tach I did not use a variable resistor instead I opted to make a fixed 280k resistor pack out of 3 resistors I had on hand It worked great - Many thanks to Oliver Scholz for his Fiero knowledge Hope this helps, Pappy

i would mess that up in about 5 seconds, i have no knowledge of any of this or tools or parts. but i will gladly send you mine and pay you to fix it?

It's already broken, give it a try. You can't mess it up more. Maybe a neighbor with soldering skills willing to work for a beer?

quote Originally posted by Hudini: It's already broken, give it a try. You can't mess it up more. Maybe a neighbor with soldering skills willing to work for a beer?

Agreed

After you get the tach out

All you need is an X-Acto knife, solder + soldering iorn, resistor(s) and beer
All can be obtained at your local Radio Shack

Except the beer of course

[This message has been edited by Pappy (edited 12-22-2011).]