speedometer 10mph off

[bkruahnndon]

alright so my speedometer has been off by 10mph ever since i bought it about a year ago. it reads 10mph fast (going 50 and it reads 60). still has stock wheels/tire sizes and its 10mph off over the whole speed band. anybody else have this problem with their 2g? what did you do to fix it?

i could not find a post already made with this sort of problem on a 2G....surely i'm not alone here.

 

[steve]

Indulge me, what size tires on on it right now?
Auto or manual?

Steve

 

[bkruahnndon]

manual

205/55R16

 

[steve]

My first thought was that maybe a PO put an auto speed sensor or gauge in but they have the same part numbers on a GST between the manual and auto's. So other than a bad sensor or gauge, I got nothing.

Steve

 

[sjgYFZ200]

Could the guage part of the dash been swapped out? ECU's changed?

 

[UrMyStlkAl]

I'd just pull the needle off and put it where it should be. How do you know its off? Driving next to someone? j/w

 

[bkruahnndon]

here in town our local law enforcement puts out a pickup truck on the side of some random streets and in the bed theres a big "scoreboard display" looking thing and its hooked up to a radar....so it shows the each driver how fast your going and blinks if your going 3mph over or whatever....so i would assume thats as accurate as it gets. also, going by the speedo in normal traffic, even the old people are flyin by me.

as for moving the needle... i would but it starts out on the peg at 0...then right when you start it seems to jump up instantly to 10 over what i'm actually doing.

 

[steve]

I'd just pull the needle off and put it where it should be.

Interesting thought. Do you have aftermarket gauge faces?

Steve

 

[UrMyStlkAl]

Well if you pull the needle off and put it where it should be, it should still go to 0 when you turn the car off. It's the same as when I replaced my gauge faces, I had to take off the needle than put it back on where it should be. If it doesn't then your right back where you started right? Just a thought.

Edit: I just read that you said it instantly jumps up to 10 over right away. I don't think this would work in that case. It would seem to be something else. Maybe if it was 10 UNDER this would work.

To get this straight, as soon as you start moving it goes to 10mph right? Than as you move it just constantly stays 10mph over

 

[bkruahnndon]

you know how close the tick marks are at the base of the gauge so its hard to tell exactly what its reading...but yes it seems correct to say that once i start moving it jumps to 10over then goes from there as i accelerate/deccelerate.

also i have the stock gauge faces

 

[CurtTSI]

I have a 97 Talon AWD that has the same problem. Fortunately mine reads only 5 mph high. I checked this against a GPS, which reads to 0.1 mph. Seems to read 5 mph high at all speeds.

 

[Defiant]

The dealer can re-calibrate it in the ECU.

 

[bkruahnndon]

is there any other way to get it recalibrated, the nearest dealer is about 3 hours away...plus i've got relatives there, and i'm sure we all know about what happens when your in the area and dont pay a visit... haha

 

[bkruahnndon]

well i finally got my datalogger in....it shows the correct speed. i guess the gauge/sensor is bad?

 

[Defiant]

manual

205/55R16

Stock tire size -check the sticker on the driver's door- is 215. There's part of it.

 

[steve]

Stock tire size -check the sticker on the driver's door- is 215. There's part of it.

Only if you have 17" rims that came on the GSX would you have a 215/50/R17. The rest of the turbo cars came with 16" rims and the stock tire is a 205/55/R16.

Steve

 

[bkruahnndon]

also wouldnt tire size make the speed vary depending on how fast your going...instead of the same reading at any speed?

 

[AWDSM]

Take a phillips screwdriver and take off the glass in front of the spedometer. Go out to a straight stretch of I-70 with a stopwatch and set your cruise to what you think is 80 mph. Use the stop watch to time how long it takes you to get from one mile marker to the next. Adjust your speed until you you are clicking off 45 seconds exactly between each marker. Then pull the needle off the speedo and put it back on at 80 mph. Or if HP is strict about the speed limit then do it at 60 mph and click off 60 second miles.