'95 GA Speedometer way off

[Dave_R]

Hello,

This is a '95 GA that I recently got. I noticed that the speedometer is way off. It seems to read about 10 mph faster than you are really going. I verified this with three separate cars going down the freeway. The "pace" cars all locked in their cruise control at 70 mph, and the GA shows 80 to 82 mph.

We have a "live" sign in our neighborhood (it's a 35 mph zone)that tells you your speed as you aproach it. I was going 35 on the GA speedometer, but the sign clocked me at 26. When I went 45 on the GA speedometer, the sign shows 35.

Is there and easy way to calibrate this?

Tires are spec size, and the gauges are origional.

(P.S. I had a '95 Skylark that did the same exact thing, but I left it alone, but this is for my daughter, so I would like it right)

Thanks!

[xeroinfinity]

you need a scan tool that can do the calibrating.

Are you sure the rim/tires are OEM size and not smaller ?

[Dave_R]

Yes, the rims are the origional OEM ones, and the tires are what the owners manual call for.

I had a '95 Skylark that acted the exact same way, and since they are similar cars, I thought there should be a "fix".

Where can I obtain one of these scan tools?

Thanks!

[doctorhrdware]

For one of the scan tools I believe that you are looking at around $5k for the GM tech 2 that is capable of calibration of the spedo.

[3100]

what is your 0-60 now?

keep your VSS wires away form ignition related components and wires

also is the face plate for your speedometer original or is it aftermarket one ?

with engine off does it show 0 mph.?

[xeroinfinity]

yeah now that I think about it, this model GA had many problems with the ICP.

Could just be bad, or as 3100 suggested out of adjustment.