Hi Guys

 

I started a tread about this before, but I have more information now.

 

My speedo doesn't tell me the correct speed I'm travelling, so I borrowed my mates SatNav yesterday and can confirm the following......

 

My Speedo is 10mph out, so when my speedo shows 30mph I'm actually doing 40pmh and when my speedo shows 50mph I'm doing 60mph etc.

 

So does this just mean that the needle was put on in the wrong place? It's a Jap import with new dial.

 

If this is the case then I just need to move it round right?

 

Sounds easy, but there is a pin sticking out from the face of the dial which stops the needle falling down. So if I remove the needle isn't the crank going to move to some other position anyway?

 

Oh and how do I get to the needle.

 

Thanks in advance

 

Spencer

have you got larger wheels? if the tyre profiles are wrong, that will throw your speedo out mate,

Spencer, if someone has had the needle off, that's your problem.

 

The way to tell is if it reads an exact amount less (or more) eg 10, should be 20, 30 should be 40, 70 should be 80 then the issue is needle position. if it reads a % higher or lower then it could be tyre/wheels/kph-mph adaptor.

 

Assuming it is the needle then you are right, the spindle has gone past where it should (eg minus 10mph) and someone has put the needle back on at 0mph (where the needle stop is).

 

You could try and remove and refit it, putting the needle on the shaft around -10 and turning it past the needle stop before pushing it fully home.

 

Or get another clock from somone and transfer your dials - they should be able to fit without removing the needles.

 

Hope this helps

My Jap import speedo is about 3-8% out with the usual mph conversion. According to my Road Angel 2

mine too... but it's one of my cars smaller problems!!

There is no way to calibrate these KPH>MPH convertors is there?

...my jap import is spot on when checked against my Roadpilot speed camera system - gets about 1mph out above 80. Have I read somewhere that removing the needle from the speedo is very difficult?

 

Wheels too big?

...my jap import is spot on when checked against my Roadpilot speed camera system - gets about 1mph out above 80. Have I read somewhere that removing the needle from the speedo is very difficult?

 

Wheels too big?

 

when you increase wheel size you must step down in tyre profile to keep the same rolling radius, some people don't as the lower the profile the harder the ride but it throws out your speedo

Was playing with DATASCAN last night and found it has a OEM and Actual tyre size setting. Will this recalibrate the speed sensor or is it just for the speed test functions?

Had me worried so I tested mine yesterday with a mates GPS, and its reading slightly under:

Speedo/GPS

30/31

40/42

50/52

60/52

80/82

100/103

 

It’s out the wrong way (ie a UK speedo would normal exaggerate the speed, so you drive slower), but at least it’s consistent and not too far adrift.

Hooray! A speedo related thread- one of the few things I can tackle. :D

 

You can calibrate the speedo.

 

Disassemble the gauge pod and you'll find the PCB has a 2 potentiometers. One sets the offset and the other does the scale.

 

To make it easier to set, I drilled 2 holes in the gauge assembly and drove with a small screwdriver sticking out the top of the dash (with the binnacle top removed). You can then drive to a GPS speed and set the pot.

 

M.

Hooray! A speedo related thread- one of the few things I can tackle. :D

 

You can calibrate the speedo.

 

Disassemble the gauge pod and you'll find the PCB has a 2 potentiometers. One sets the offset and the other does the scale.

 

To make it easier to set, I drilled 2 holes in the gauge assembly and drove with a small screwdriver sticking out the top of the dash (with the binnacle top removed). You can then drive to a GPS speed and set the pot.

 

M.

 

Mark

 

So you don't just think that I should take the needle off and try and replace it 10mph up?

 

Spencer

Mark

 

So you don't just think that I should take the needle off and try and replace it 10mph up?

 

Spencer

 

I definitely try and adjust it on the pots, before you risk breaking it when you try to take off and put the needle back on!!

 

IIRC, Lymon posted a link to how to put the needle back on without damaging it...

 

good luck!

Hooray! A speedo related thread- one of the few things I can tackle. :D

 

You can calibrate the speedo.

 

Disassemble the gauge pod and you'll find the PCB has a 2 potentiometers. One sets the offset and the other does the scale.

 

To make it easier to set, I drilled 2 holes in the gauge assembly and drove with a small screwdriver sticking out the top of the dash (with the binnacle top removed). You can then drive to a GPS speed and set the pot.

 

M.

 

Mark

 

It's about time I sorted this problem out.

 

I was wondering if you fancied helping me?

 

How about I drive over to see you one weekend and you help me fix this. I will make it worth your while. Oh that sounds wrong. :x:

 

Hope to speak with you soon :dance:

 

Spencer

Hey guys,

I've got a speedo problem too on my jap import, when i get to 95mph the needle drops to 0. The car still runs fine but speedo has no readings, when I drop back to 95 it comes back to life again.

Mark

 

It's about time I sorted this problem out.

 

I was wondering if you fancied helping me?

 

How about I drive over to see you one weekend and you help me fix this. I will make it worth your while. Oh that sounds wrong. :x:

 

Hope to speak with you soon :dance:

 

Spencer

 

Got your email too mate.

 

I think I was wrong in what I said above- having recently helped another forum member with his clocks, I don't believe either of the potentiometers adjust the offset. What Big Marty posted is correct- if the speed is out by a constant amount, it's the needle position that's the problem.

 

In terms of how to get the clocks out, that's here: http://www.300zx.co.uk/forums/showpost.php?p=297744&postcount=3

 

Then it's a question of removing the needle and replacing it in the correct position. I've never done that so I can't offer any pointers! :(

 

It's also worth looking closely at the needle as it is now to see if the previous person who removed it broke it in the process- if it's been glued back on to the spindle, I'd say your chances of getting it off without breaking it again are poor.

 

I can still give you hand if you like?

 

Mark

Badder- thread hijack noted ;)

 

My guess is you've got a faulty km/mph converter box, but I've never used one so I can't be sure.