Discussion
Check the air gap between the speed sensor unit and the drive on the diff. If the air gap is too big the signal will be poor. If the sensor is touching then it will be damaged. If you can just get a piece of card to slide between the sensor and the drive then its about right.
If this does not cure it then probably needs the speedo repaired. http://www.speedycables.com/
The repair may take around 6 weeks.
If this does not cure it then probably needs the speedo repaired. http://www.speedycables.com/
The repair may take around 6 weeks.
This is the sensor: http://tvr-parts.com/tvr-parts/part-details/tvr-m0...
I've been thinking my speedo needs repair but maybe it's the sensor after all !
Mine jumps about and usually reads about 10 mph to high, but can read 140 when I'm doing 90 mph,
It's about time I checked the gap and made a decision.
I see it says 10-12 thou as a gap so pretty small then!
Mine jumps about and usually reads about 10 mph to high, but can read 140 when I'm doing 90 mph,
It's about time I checked the gap and made a decision.
I see it says 10-12 thou as a gap so pretty small then!
Mines just a touch less than a 1mm gap, unless it's fubbered it seems more than close enough to take its readings!
My clock is still the likely culprit as it often reads 30 mph when I've just stopped.
Returning to the car it then starts at zero and doesn't move until about 15-20 mph but it's always done that.
My clock is still the likely culprit as it often reads 30 mph when I've just stopped.
Returning to the car it then starts at zero and doesn't move until about 15-20 mph but it's always done that.
Mine grossly over reads at all speeds - indicates 100 at 85mph(GPS) - and is on standard wheels/tyres, original box and GKN diff with 3.31 ratio so a fault in the unit itself I guess.
As Speedy are alleged to be a bit slow doing repairs (up to 6 weeks) and not wanting to be off the road during the summer, I bought one of these so I don't get a ticket.
http://www.ebay.co.uk/itm/221587766584
As Speedy are alleged to be a bit slow doing repairs (up to 6 weeks) and not wanting to be off the road during the summer, I bought one of these so I don't get a ticket.
http://www.ebay.co.uk/itm/221587766584
Never ceases to amaze me how you can come onto PH intending to post a question about something and there is already one on there from today or the day before, with exactly the same problem ha ha.
My speedo has always been reliable but last week or so it has read zero until I reach about 20mph. Between 15-20mph it flicks up and down a bit. It used to read OK down to around 10mph.
Have just had the rear diff replaced, so it seems from the above like I need to look at the gap as it will have been changed by the diff replacement no doubt.
Thanks PH !
My speedo has always been reliable but last week or so it has read zero until I reach about 20mph. Between 15-20mph it flicks up and down a bit. It used to read OK down to around 10mph.
Have just had the rear diff replaced, so it seems from the above like I need to look at the gap as it will have been changed by the diff replacement no doubt.
Thanks PH !
2 points:
These guys ( https://www.etbinstruments.com/ ) reconditioned my speedo, inc. straightening out the face, for about £60 I think inc. VAT & P&P and all within a couple of weeks.
Also, just check that the wires onto the speedo sensor are well connected. Loose connections here can result in exactly the same syptoms as incorrectly gapped sensor.
These guys ( https://www.etbinstruments.com/ ) reconditioned my speedo, inc. straightening out the face, for about £60 I think inc. VAT & P&P and all within a couple of weeks.
Also, just check that the wires onto the speedo sensor are well connected. Loose connections here can result in exactly the same syptoms as incorrectly gapped sensor.
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