TPS Source?

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Mounting new tire now. Gonna da couple hundred miles tomorrow weather permitting with some Fuel injector cleaner. Runs better with the TPS but still has a stumble at 3k rpm.
 

yamahale

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I replaced my 06 TPS simply because: 95,000 miles but new to me, part has been superceded since 2006, we had one on the shelf, and my killer employee discount lol. I found the original adjustment was almost fully 'retarded', and using the dash readout adjusting the new one to 99% required almost full 'advance' in the slots. Along with the other fixes etc I did it now has a little snarl that wasnt there before through the Delkevics and pulls very noticeably harder. The on/off is diminished but still there though.
 
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Thanks. I do not have a manual to do the read out adjustment but it seems best at slightly more ccw than center after multiple tests, which is about where the original one was. More clockwise the throttle hesitates, more ccw the idle goes lower and won't stay running.
 

Bounce

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My understanding of the TPS mechanics (could be wrong).

It's a rheostat with a mechanical "arm" swiping along a series of conducting "contact points" which report where in the arc, the "arm" is (throttle position). The TPS failure was due to excessive wear of the contacts when a lot of time was spent in the same speed range (wearing the contact points in the well-used portion of the arc).

Nothing to add on how to avoid the wear but I always thought that understanding the underlying mechanisms makes diagnosing and such easier.
 

Old Guy

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My understanding of the TPS mechanics (could be wrong).

It's a rheostat with a mechanical "arm" swiping along a series of conducting "contact points" which report where in the arc, the "arm" is (throttle position). The TPS failure was due to excessive wear of the contacts when a lot of time was spent in the same speed range (wearing the contact points in the well-used portion of the arc).

Nothing to add on how to avoid the wear but I always thought that understanding the underlying mechanisms makes diagnosing and such easier.

I did take my old one apart and there was wear in a small portion of the very flimsy looking plating. It wasn't terribly obvious to me, but I examined it with an 8X lupe and could see it.

The service manual advises to handle the new one carefully and if you drop it, don't use it. If you happen to drop the new one replace it. You better believe I was very, very careful ;) But that caution made me wonder if some of them just didn't get handled roughly at the factory and cause the rash of failures we seem to have had.
 

TooManyBikes

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Somebody posted here how they had fried a TPS or some other sensitive device by measuring the resistance with an ohm meter. Does anyone recall the details?

Would hate for someone else to have a sad learning experience with a multimeter, if someone else has already done so and posted it.
 

FJR Flyer

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I did take my old one apart and there was wear in a small portion of the very flimsy looking plating. It wasn't terribly obvious to me, but I examined it with an 8X lupe and could see it.

The service manual advises to handle the new one carefully and if you drop it, don't use it. If you happen to drop the new one replace it. You better believe I was very, very careful ;) But that caution made me wonder if some of them just didn't get handled roughly at the factory and cause the rash of failures we seem to have had.
I wonder if mine got beat up during the 2nd gear recall work. It surfaced after I got it back.
 

Bounce

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Since so many functions run back to the ECU, a V/O meter can be problematic. Those circuits are easy to fry with just the load on the meter.
 

yamahale

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Somebody posted here how they had fried a TPS or some other sensitive device by measuring the resistance with an ohm meter. Does anyone recall the details?

Would hate for someone else to have a sad learning experience with a multimeter, if someone else has already done so and posted it.
a VOM is typically only 9V so I doubt it could harm a simple copper winding. They are used to test ECU's which are arguably the most sensitive component out there. I am curious now about the incident you mean......
 

RossKean

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a VOM is typically only 9V so I doubt it could harm a simple copper winding. They are used to test ECU's which are arguably the most sensitive component out there. I am curious now about the incident you mean......
The TPS is a resistive material on a board with a wiper that rotates over the surface (no copper windings). Photo is from a great thread by ionbeam:


1665058670376.png

I agree that the low voltage and current used to measure resistance using a VOM would not damage the TPS but I couldn't say for certain that it couldn't harm something else that the TPS is hooked up to. (You would want to remove it from the circuit anyway before any measurements of that sort.)
 
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Bounce

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a VOM is typically only 9V so I doubt it could harm a simple copper winding. They are used to test ECU's which are arguably the most sensitive component out there. I am curious now about the incident you mean......
Sorry. It was a warning we got years ago. I have incorporated it and never questioned it. As a result, I've not fried an ECU. Given your comment, I suspect I am about to be explained to about how that was wrong and I would probably not have fried an ECU anyway.

I would note in my defense, I wasn't thinking about the TPS but something that might be affected up stream. It's one reason why I bench tested my TPS instead of doing it in-place. Maybe overkill but meh.
 

RossKean

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I would note in my defense, I wasn't thinking about the TPS but something that might be affected up stream. It's one reason why I bench tested my TPS instead of doing it in-place. Maybe overkill but meh.
I'm not sure how you could easily test it without removing it from the circuit. Easier to unplug it and be able to meter the connections directly rather than break insulation or try to back probe the connector. (Not to mention the unknown contribution of components attached to the TPS.)
Your method is not only appropriate but vastly easier than any alternative.
The following is a screenshot for testing the TPS from the FSM. This is for a Gen II but procedure, if not values, should be similar for other generations. Note: While this checks the resistance range of the device, it doesn't test whether there might be places where resistive material is worn and the wipers might not make good contact. Still, it is a test that tells whether the part is completely FUBAR. They are using an ohmmeter with the TPS disconnected from the system... Their spec just uses the value for maximum resistance without any specs for minimum (zero?) or mid.

1665061845541.png
 
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exo55c

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Following up on my original post...
I ran diagnostics on the original unit and then on the known-good, used TPS from Kelvin.

Original TPS: d:01 16 ----> 99

Replacement TPS: d:01 15 ----> 101

Do I need to rotate it so it reads 100?
 

exo55c

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View attachment 2865

I doubt it will make a big difference but if you adjust the angle to get the 101 down to 100, the 15 might drop too low.
I think I would try it as is.

Gotcha. But first things first. My rear tire wore down to the belts on my last ride thru Lolo Pass in MT. I picked up a pair of Pirelli Angel ST with 2022 date codes to mount this week. Great price on a discontinued tire.
 
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