1G 90 Tach Quit working

[rally864]

The other day I was running my car and the tach was acting up. It would bounce around and then would level out at the work for a while. Now the tach doesn't work at all. Any ideas of what it could be. The car is completely stock.

Also how hard would it be to wire in a aftermarket tach?
Where would you hook it up to?
Thanks

 

[tsi1991awd]

Seeing as you have a 90, I am almost 100% certain that it is your noise filter.

The noise filter is a tiny rectangular metal piece that has a 2 wire connector coming off of it. It is attached to the underside of your intake manifold on the manifold stay bracket. Feel around for it. Once you replace that, you'll be good to go.

 

[rally864]

Where would you be able to pick up a new noise filter?

 

[tsi1991awd]

You could get one at a junk yard or check the classifieds and see if anyone is parting their 90 out.

I'm not sure how much one costs at the dealership but I found mine off of a Hyundai Elantra with the 4G63 engine.

 

[NeMiZiS]

Is this a picture of the noise filter?
The smaller rectangular one?
I think it is why my Tach isn't working and I want to know what it looks like.
Sorry about the size of the picture, it was the best I could find.

 

[tsi1991awd]

No, thats not the noise filter...it's smaller than that. If you have a 91+ then you dont use a noise filter for tach signal. ONLY the 90 uses it. I will take a picture of the noise filter when I go back outside. I have it mounted to the back of my manifold but if you havent touched yours, it will be under the manifold.

 

[XiKeiyaZI]

Doesn't the PTU control the Tach? Correct me if I'm wrong... but if that's faulty then your tach SHOULD act up?

 

[williamsoa]

No, the 1990 tach module on the coil pack controls the Tach signal. The PTU affects the firing of the coils.

 

[dsmer1994]

Seeing as you have a 90, I am almost 100% certain that it is your noise filter.

The noise filter is a tiny rectangular metal piece that has a 2 wire connector coming off of it. It is attached to the underside of your intake manifold on the manifold stay bracket. Feel around for it. Once you replace that, you'll be good to go.

Same thing happend to a friend of mine on his 91 and it was the noise filter! so i would have to 100% agree with you here most junkyards should have one our po dunk town of 900 people had one haha so anywhere else should aswel he paid like 10 bucks for it or something.