1985 Supra speedometer 20MPH over what it should be

chrismc410 · 09-17-2005, 02:01 AM

Hi

I bought a 1985 Supra recently and discovered that the speedometer is 20MPH over what it should be. For example, if it says 40MPH, you're doing 20MPH and 85MPH, you're doing 65MPH. Its a manual transmission, as far as I know, the orginal, I've tried a new gauge cluster, same thing. I"m told I might need a gear to slow the cable down, but I have no idea what cable I need or how to find it. I'm told there are five possible gears. As far as I know, the car is stock, engine, wheels match exactly what the glove box says, so what can be done and who can do this kind of work?

Thanks

tonster · 09-17-2005, 02:20 AM

When you're just sitting does it read 20 mph? The instrument cluster analog or digital? It could just be that you need to reset the zero on the needle if it's analog and that is the case, otherwise I don't know. If it's digital maybe there's a short adding unwanted voltage somehow? It doesn't make sense that it would always be 20 mph off. I think the speedometer cable hooks directly into the transmission so thats where you would look I'd guess.

chrismc410 · 09-17-2005, 03:22 AM

When stopped, its at zero and its analog 130MPH speedometer

hangsupra · 09-24-2005, 10:13 PM

first of all take out your cluster n turn side way n see if the mph stays at 0 mph or it move back n forth. if it move back n forth then its your speeding metter.... replace with a new one. if it stays the same at 0 mph then its something else. let me know how u get to work.

86supraNa · 10-17-2005, 03:12 AM

i was driveing on the highway going bout80 and a toyota camery was right next seepeding up trying to pass me so i sped up to about 110 and it kept going to about 130 and bounceing i was goina prettyfast but im not sure if i was really going 130 cuz the last time i tryed to top it out it only hit 110 so maybe i got same problem felt more like 115 or 120 though im confussed

but when im going 20mph it says 20mph so i duno

hangsupra · 10-17-2005, 07:16 PM

but now does your speeding metter still working...

Quote:

Originally Posted by 86supraNa

i was driveing on the highway going bout80 and a toyota camery was right next seepeding up trying to pass me so i sped up to about 110 and it kept going to about 130 and bounceing i was goina prettyfast but im not sure if i was really going 130 cuz the last time i tryed to top it out it only hit 110 so maybe i got same problem felt more like 115 or 120 though im confussed

but when im going 20mph it says 20mph so i duno

hangsupra · 10-17-2005, 07:35 PM

after you speed up for a bit n your car keep bounce up n down for a few sec. n your cable just stop n decrease in the middle of the road... does it decrease back to the ZERO mph position... if so... then you busted your speeding cable... in this point... i pretty sure its your adapter that conect from the tranny to the adapter... the adapter looks like the L shape... it goes between the tranny n the speed cable that goes to your dash board... left up your car n untight that adapter n take it out... n this is how you testing.. at the other end... you can see a caple line it looks like a needle... you tonna turn or spindding... if it didnt spend freely then its toasted... if it does spend freely then its still good shape... the adapter is only for few car... not all the mk2 have it... after you check on that... if it spend freely then please do the same thing on your speed cable from the tranny to the dash board... untight both end n do the same thing on it... after that you didnt find anything then i guess its your speed diameter gauge then... thats the one on your dash board... hope this work on you guy with the trouble speeding cable... hehe... correct me if i wrong guy.... heheh...

86supraNa · 10-18-2005, 05:26 AM

oooooooooopppps

86supraNa · 10-18-2005, 05:27 AM

it seems to be fine actully i think the cold air helped me top out at higher speeds cuz last time i drove fast it was in the summer and i never took it on a open road with lots of space like i did this weekend the car runs pretty good i bought it stock in june and put intake and a nice muffler on it i finally got a good feel for this car so maybe i was just driveing and shifting better / is it posible for a 86 supra with a intake and proformance muffler to do 130? cuz i rreally did have that car moveing im thinking bout selling it though got a jdm probe i been fixing up p) so any1 wants 2 ask ? bout my supra it might be up for grabs soon so make me a offer i live in NJ

i will miss rwd though p( drifting is fun

hangsupra · 10-18-2005, 09:34 PM

dont worry... i have a '89 ford probe gt-turbo with the mazda motor on it... n probe still do the job on me to... hehe... n i selling my probe to whoever want it to... hehe...

09-17-2005, 02:01 AM	#1
chrismc410 Stock Join Date: Sep 2005 Posts: 2	1985 Supra speedometer 20MPH over what it should be Hi I bought a 1985 Supra recently and discovered that the speedometer is 20MPH over what it should be. For example, if it says 40MPH, you're doing 20MPH and 85MPH, you're doing 65MPH. Its a manual transmission, as far as I know, the orginal, I've tried a new gauge cluster, same thing. I"m told I might need a gear to slow the cable down, but I have no idea what cable I need or how to find it. I'm told there are five possible gears. As far as I know, the car is stock, engine, wheels match exactly what the glove box says, so what can be done and who can do this kind of work? Thanks

10-17-2005, 03:12 AM	#5
86supraNa Stock Join Date: Oct 2005 Posts: 4	happend to me today 2 i was driveing on the highway going bout80 and a toyota camery was right next seepeding up trying to pass me so i sped up to about 110 and it kept going to about 130 and bounceing i was goina prettyfast but im not sure if i was really going 130 cuz the last time i tryed to top it out it only hit 110 so maybe i got same problem felt more like 115 or 120 though im confussed but when im going 20mph it says 20mph so i duno Last edited by 86supraNa; 10-17-2005 at 03:25 AM.

10-18-2005, 05:26 AM	#8
86supraNa Stock Join Date: Oct 2005 Posts: 4	oooooooooopppps Last edited by 86supraNa; 10-18-2005 at 05:30 AM.

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09-17-2005, 02:20 AM	#2
tonster Stock Join Date: Mar 2005 Posts: 14	When you're just sitting does it read 20 mph? The instrument cluster analog or digital? It could just be that you need to reset the zero on the needle if it's analog and that is the case, otherwise I don't know. If it's digital maybe there's a short adding unwanted voltage somehow? It doesn't make sense that it would always be 20 mph off. I think the speedometer cable hooks directly into the transmission so thats where you would look I'd guess.

09-17-2005, 03:22 AM	#3
chrismc410 Stock Join Date: Sep 2005 Posts: 2	When stopped, its at zero and its analog 130MPH speedometer

09-24-2005, 10:13 PM	#4
hangsupra 12psi boost Join Date: Jan 2005 Location: 209 area in cali. Posts: 397	first of all take out your cluster n turn side way n see if the mph stays at 0 mph or it move back n forth. if it move back n forth then its your speeding metter.... replace with a new one. if it stays the same at 0 mph then its something else. let me know how u get to work.

10-17-2005, 07:35 PM	#7
hangsupra 12psi boost Join Date: Jan 2005 Location: 209 area in cali. Posts: 397	after you speed up for a bit n your car keep bounce up n down for a few sec. n your cable just stop n decrease in the middle of the road... does it decrease back to the ZERO mph position... if so... then you busted your speeding cable... in this point... i pretty sure its your adapter that conect from the tranny to the adapter... the adapter looks like the L shape... it goes between the tranny n the speed cable that goes to your dash board... left up your car n untight that adapter n take it out... n this is how you testing.. at the other end... you can see a caple line it looks like a needle... you tonna turn or spindding... if it didnt spend freely then its toasted... if it does spend freely then its still good shape... the adapter is only for few car... not all the mk2 have it... after you check on that... if it spend freely then please do the same thing on your speed cable from the tranny to the dash board... untight both end n do the same thing on it... after that you didnt find anything then i guess its your speed diameter gauge then... thats the one on your dash board... hope this work on you guy with the trouble speeding cable... hehe... correct me if i wrong guy.... heheh...

10-18-2005, 05:27 AM	#9
86supraNa Stock Join Date: Oct 2005 Posts: 4	it seems to be fine actully i think the cold air helped me top out at higher speeds cuz last time i drove fast it was in the summer and i never took it on a open road with lots of space like i did this weekend the car runs pretty good i bought it stock in june and put intake and a nice muffler on it i finally got a good feel for this car so maybe i was just driveing and shifting better / is it posible for a 86 supra with a intake and proformance muffler to do 130? cuz i rreally did have that car moveing im thinking bout selling it though got a jdm probe i been fixing up p) so any1 wants 2 ask ? bout my supra it might be up for grabs soon so make me a offer i live in NJ i will miss rwd though p( drifting is fun

10-18-2005, 09:34 PM	#10
hangsupra 12psi boost Join Date: Jan 2005 Location: 209 area in cali. Posts: 397	dont worry... i have a '89 ford probe gt-turbo with the mazda motor on it... n probe still do the job on me to... hehe... n i selling my probe to whoever want it to... hehe...