Discussion
ACT do an upgrade but I havent plucked up the courage to buy it!.......
https://www.actproducts.co.uk/product/sp002-rover-...
https://www.actproducts.co.uk/product/sp002-rover-...
upgrade or new old stock, not much in it money wise!
https://www.ebay.co.uk/itm/363535388298?_trkparms=...
https://www.island-4x4.co.uk/throttle-potentiomete...
https://www.ebay.co.uk/itm/363535388298?_trkparms=...
https://www.island-4x4.co.uk/throttle-potentiomete...
Edited by phillpot on Sunday 19th September 11:10
I made one for my 350i, I found an 'active' pot which was rated for around a million operations (I worked out maybe 60k miles worth).
I had to invert the signal electronically because it rotates in the 'wrong' direction (throttle closed is +5V, dropping to 0V throttle open), but that was a simple transistor circuit.
It seemed to work quite well and the car was perfectly driveable. I can post some pics when I get around to taking them. It does replace the big fat 3-fastener one.
I had to invert the signal electronically because it rotates in the 'wrong' direction (throttle closed is +5V, dropping to 0V throttle open), but that was a simple transistor circuit.
It seemed to work quite well and the car was perfectly driveable. I can post some pics when I get around to taking them. It does replace the big fat 3-fastener one.
adam quantrill said:
I made one for my 350i, I found an 'active' pot which was rated for around a million operations (I worked out maybe 60k miles worth).
I had to invert the signal electronically because it rotates in the 'wrong' direction (throttle closed is +5V, dropping to 0V throttle open), but that was a simple transistor circuit.
It seemed to work quite well and the car was perfectly driveable. I can post some pics when I get around to taking them. It does replace the big fat 3-fastener one.
Would be keen to know what you did and what parts you used as it is looking like I will have to go that route for a customer car.I had to invert the signal electronically because it rotates in the 'wrong' direction (throttle closed is +5V, dropping to 0V throttle open), but that was a simple transistor circuit.
It seemed to work quite well and the car was perfectly driveable. I can post some pics when I get around to taking them. It does replace the big fat 3-fastener one.
Steve
I can't find the original part I used. But in the mean time Vishay have started making what is probably even more durable, and also good temperature rating (-40 to 125C).
Something like this from RS might do the trick: https://uk.rs-online.com/web/p/potentiometers/1680...
As it's a different mounting, you will have to make up an adapter plate. I can't remember the shaft coupling I seem to recall that it sticks out of the throttle body? So with the one above, maybe use an aly U section for the mechanical adapter and a shaft coupling to mate them together.
Just make sure the rotation is correct - I think it's clockwise (which is correct for the part above) but I might be wrong, If you get that right it should wire straight in to the 4CU. Also you want a 90 degree electrical travel probably, to match the original sweep angle.
Something like this from RS might do the trick: https://uk.rs-online.com/web/p/potentiometers/1680...
As it's a different mounting, you will have to make up an adapter plate. I can't remember the shaft coupling I seem to recall that it sticks out of the throttle body? So with the one above, maybe use an aly U section for the mechanical adapter and a shaft coupling to mate them together.
Just make sure the rotation is correct - I think it's clockwise (which is correct for the part above) but I might be wrong, If you get that right it should wire straight in to the 4CU. Also you want a 90 degree electrical travel probably, to match the original sweep angle.
Here's maybe a better possibility:
https://www.digikey.at/product-detail/en/bourns-in...
Electrical travel is 100 degrees, so might be a better match.
The one I used was a polymer device, I think these hall effect ones are more durable, in the region of 50 million operations.
Maybe better value for money: https://www.digikey.at/product-detail/en/tt-electr...
Another approach I was considering is to put a hall sensor and magnet into an existing original pot, replacing the wiper and carbon track. This would keep the 'original look'. I'll have a think about this...
If anyone has any old and worn out ones they can send me, I'll try doing some prototypes.
https://www.digikey.at/product-detail/en/bourns-in...
Electrical travel is 100 degrees, so might be a better match.
The one I used was a polymer device, I think these hall effect ones are more durable, in the region of 50 million operations.
Maybe better value for money: https://www.digikey.at/product-detail/en/tt-electr...
Another approach I was considering is to put a hall sensor and magnet into an existing original pot, replacing the wiper and carbon track. This would keep the 'original look'. I'll have a think about this...
If anyone has any old and worn out ones they can send me, I'll try doing some prototypes.
Edited by adam quantrill on Monday 20th September 19:45
Pumpkin123 said:
Very interesting 
Yes I have done this repair myself, and it works for a while, but....
What also happens is that the pips on the wiper wear down and acquire sharp edges. These cut through the freshly-exposed carbon track in a few thousand miles, and you're back to square one. A proper mod would be to somehow also repair the pips, but even then, it will still wear through eventually.
What also happens is that the pips on the wiper wear down and acquire sharp edges. These cut through the freshly-exposed carbon track in a few thousand miles, and you're back to square one. A proper mod would be to somehow also repair the pips, but even then, it will still wear through eventually.
adam quantrill said:
I can't find the original part I used. But in the mean time Vishay have started making what is probably even more durable, and also good temperature rating (-40 to 125C).
Something like this from RS might do the trick: https://uk.rs-online.com/web/p/potentiometers/1680...
Been conversing to Vishay today. The 981 is pretty near perfect but does not go down below 0.5 volt so the ECU will not see a closed throttle which will mess it up big time. pity as it is Hall effect which means little or no wear issues. They have proffered another version which is a 'carbon track' version but i am waiting for them to come back with the voltage figures.Something like this from RS might do the trick: https://uk.rs-online.com/web/p/potentiometers/1680...
I'm also waiting for data to come in on a Penny + Giles version which will no doubt be much more expensive but it was designed specifically for Jenvey so should be pretty good.
Will keep you updated.
Steve
ETA in case anyone is wondering the other 'repair' suggestions are out for me as the 'carbon' track on this one is pealing of in flakes so it is well dead.
Edited by Steve_D on Tuesday 21st September 20:31
Try the TT electronics one then see the data sheet, it goes down to 0,2V
https://www.digikey.at/en/datasheets/tt-electronic...
I hadn't noticed the min and max output values from the Vishay one, yes that is a bit of a limitation, although one approach if you prefer that one mechanically is to put a silicon diode in series with the output, which will drop 0.6V off it, so you can get that 0.325V minimum up to around 4V maximum. A more sophisticated approach would be to use a small signal NPN transistor as an emitter follower, this will similarly follow the input but 0.6V lower.
https://www.digikey.at/en/datasheets/tt-electronic...
I hadn't noticed the min and max output values from the Vishay one, yes that is a bit of a limitation, although one approach if you prefer that one mechanically is to put a silicon diode in series with the output, which will drop 0.6V off it, so you can get that 0.325V minimum up to around 4V maximum. A more sophisticated approach would be to use a small signal NPN transistor as an emitter follower, this will similarly follow the input but 0.6V lower.
Edited by adam quantrill on Tuesday 21st September 21:29
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