Potential fix for worn throttle potentiometers
Discussion
Hi,
While restoring my 350i it became apparent that the throttle pot was not working as it should. Following the SD1 blog I took it apart (gently) to find a broken wire and a completely trashed resistance track.
I have ordered something which may be a suitable replacement which will require some fettling to fit but in the meantime came across a product which may be of interest to others.
It is called Superslide by Heckscher co.uk which is a (graphite/lead?) suspension in a volatile liquid which may leave a suitable resistance band/track which could replace the original. It is probably very reasonably priced (approx 35.00 inc postage for 60ml) for it's intended use (piano tuning).
I know of one person who has used this product to repair old Hi-Fi equipment (potentiometers) with success but I've no idea whether it will work on a Rover TPS (The circular early ones).
As I am rubbish with soldering electronics, I am not going to try this myself, but if anyone out there wants to give it a try, over to you. I'd be happy to pay a small fee to get mine repaired and keep the engine somewhat original, and there may be others who would want the same service.
While restoring my 350i it became apparent that the throttle pot was not working as it should. Following the SD1 blog I took it apart (gently) to find a broken wire and a completely trashed resistance track.
I have ordered something which may be a suitable replacement which will require some fettling to fit but in the meantime came across a product which may be of interest to others.
It is called Superslide by Heckscher co.uk which is a (graphite/lead?) suspension in a volatile liquid which may leave a suitable resistance band/track which could replace the original. It is probably very reasonably priced (approx 35.00 inc postage for 60ml) for it's intended use (piano tuning).
I know of one person who has used this product to repair old Hi-Fi equipment (potentiometers) with success but I've no idea whether it will work on a Rover TPS (The circular early ones).
As I am rubbish with soldering electronics, I am not going to try this myself, but if anyone out there wants to give it a try, over to you. I'd be happy to pay a small fee to get mine repaired and keep the engine somewhat original, and there may be others who would want the same service.
I know that ACT do offer an upgrade kit also. https://www.actproducts.co.uk/product/sp002-rover-...
Thanks for the tip, Nick.
In fact a simpler solution is to remove and re-fit the slider slightly offset to where it originally ran, and it will wear a new groove.
But part of the problem is usually that the slider itself has a dimple where it contacts the track. By the time it has cut through the track, the dimple has worn down too, and is left with sharp edges, which soon wear through the track again.
The slider is made of a bronze style material, so soldering onto it would probably be too soft. Although I suppose if you soldered a small brass ball on, that might work.
I eventually found a pot that would work for a million operations, which I fitted to the 350i, although it's mechanically different and needed a new bracket to mount it plus some electronics to invert the signal. If you assume 10 operations per mile then 10k miles is 100k operations, which is the rated life of many standard electronics pots.
In fact a simpler solution is to remove and re-fit the slider slightly offset to where it originally ran, and it will wear a new groove.
But part of the problem is usually that the slider itself has a dimple where it contacts the track. By the time it has cut through the track, the dimple has worn down too, and is left with sharp edges, which soon wear through the track again.
The slider is made of a bronze style material, so soldering onto it would probably be too soft. Although I suppose if you soldered a small brass ball on, that might work.
I eventually found a pot that would work for a million operations, which I fitted to the 350i, although it's mechanically different and needed a new bracket to mount it plus some electronics to invert the signal. If you assume 10 operations per mile then 10k miles is 100k operations, which is the rated life of many standard electronics pots.
Edited by adam quantrill on Tuesday 19th January 15:20
Yes moving the slider would work but you'd need to be very precise and as you predicted my slider has worn down the metal points anyway, and my ability to solder a tiny metal ball onto the slider is less than non-existant! So not for me.
I've sourced another pot and hope to fabricate a bracket and connectors but I won't be going there for quite a while yet but that's another story:-
Meanwhile I almost got her running on twin SU's smooth enough to pass the MOT emissions (the only fail apart from one low headlight aim) only for the blinking water pump to fail. So now I'm slopping out the garage and thinking Davies Craig Electric Water Pump. Lucky I didn't go waterless coolant all over the floor.
I've sourced another pot and hope to fabricate a bracket and connectors but I won't be going there for quite a while yet but that's another story:-
Meanwhile I almost got her running on twin SU's smooth enough to pass the MOT emissions (the only fail apart from one low headlight aim) only for the blinking water pump to fail. So now I'm slopping out the garage and thinking Davies Craig Electric Water Pump. Lucky I didn't go waterless coolant all over the floor.
Gassing Station | Wedges | Top of Page | What's New | My Stuff