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TPS Throttle Position Sensor


docc

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Cannot get the throttle position to be reliable after changing it this last time. Planning on installing a new TPS and hoping for a resolution . . .

Once again, there are many, many contributors to the various V11 stumble/hiccup/cough/falter. No doubt, several of them can combine to make for challenging fettling. :luigi:  :blink:

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Trying, rather earnestly, to set this TPS again after diligently cleaning the (really dirty) throttle body bores and plates (yeah, I had skipped that step) I really thought I had pinned this down. But then . . .

With the multimeter set to resistance (kΩ), rolling the throttle ever-so-slowly, I caught this reading several times at low throttle openings. Yep, that means the TPS goes "open"/disconnects. At which point the ECU just goes to sleep . . . zzzzzzzzzzzzz

IMG_9773.jpg

FWIW, I can never see these TPS failures looking at the mV output. Very telling when the TPS goes "open"/dead looking at the resistance through the TPS/potentiometer at various throttle openings.

Makes me more more hopeful the new TPS will address this new falter . . .

 

 

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docc, you have, of course, excluded the possibility that the multimeter has a dickey connection?

 

No offense meant, but someone has to ask the dumb questions... B)

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Nothing wrong with that thinking. Or that the input was exceeding the selected range and causing the "1" to display and appear like an open circuit. 
 

That I could get it to repeat consistently gently rolling the throttle on and off at that throttle position (with the meter, but also while riding) has me thinking it worthwhile to change the TPS. The replacement arrived today.

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Otherwise, other than the TPS, I have no explanation for what the Sport is doing now. I'll know tomorrow if this new TPS addresses the issue.

At that point, I will have feedback on the ca-cycleworks TPS and will likely split these TPS posts to a dedicated TPS thread.

At which point I don't want to type "TPS" again for a long time . . .  :blink:

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2 minutes ago, docc said:

...other than the TPS, I have no explanation for what the Sport is doing now....

What you wrote about "consistenly repeatable" sounds a lot like you are on the right track. That is one of the fundamentals of isolating problems. :)

 

4 minutes ago, docc said:

At which point I don't want to type "TPS" again for a long time . . .  :blink:

Why not? It is so easy to type: left forefinger,right ring finger, left ring finger. Nothing to it.  :P:grin:

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The TPS replacement checked out. The setting is still not perfect, but the awful (almost unrideable) hesitation/falter is gone. This is my 4th TPS. Number two was a PF4C for Harley-Davidson and #3/#4 are ca-cycleworks. First two lasted 50-60,000 miles each. This last ca-cycleworks about 19,000. That it "went bad" after it was adjusted makes me wonder if the method of tapping the TPS back and forth with a screwdriver handle to get the delicate setting could be suspect practice. That is the only action I can imagine that could have damaged the TPS during the tune-up. :huh2:

What with my decidedly worn throttle body shafts, finding the "fully and completely closed" throttle position remains enigmatic. I can change the reading about 30 mV pushing the throttle crank closed along with deflecting the shaft laterally.  My understanding is that is about four "steps" on the mapping.

A moving target . . .

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1 hour ago, docc said:

What with my decidedly worn throttle body shafts, finding the "fully and completely closed" throttle position remains enigmatic.

Sounds like your TB’s are due for a rebuild..

 

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14 minutes ago, Speedfrog said:

Sounds like your TB’s are due for a rebuild..

 

Oh, for absolute certain! I have a replacement rack with low miles (about 14,000) that I could "just swap out."  I say that in quotes because the frame has to be crabbed to replace the throttle body rack (they don't just slide out to one side).

Also, whether I should first rebuild the low mile throttle bodies or, at least, have the injectors cleaned.

I keep telling myself, "This is what I do for fun." :sun:

Thanks, again, @Speedfrog for posting that excellent Throttle Body Rebuild tutorial detailed by @Lucky Phil !

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Yeah, definitely a “fun” project for the rainy season. Having the injectors cleaned is the easy part, I reckon I would if they’ve been on the shelf for any length of time. 

2 hours ago, docc said:

That excellent Throttle Body Rebuild tutorial detailed by @Lucky Phil !

I think that I’ve said it before, and no offense to all the great contributors to this forum, but I miss @Lucky Phil's vast knowledge and no-nonsense approach to all things technical. 

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I have a bad experience with ca cyclework TPS, maybe due to moisture, as it is not a proper sealing around the TPS. The bike was not rideable,  and become good when a old original TPS was installed.  As a solution to this I put some water resistance grease around the TPS, have worked well since

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Since I got the bike out of the shop, it's run a bit better but was getting an off throttle backfire, particular when I downshifted.  Since the bike was dyno tuned, I'd thought they might've been just too aggressive with timing and/or fuel.  Anyway I was going to take it back.  Then Sunday, I took to the DGR ride and the problem got quite bit worse, lots of backfiring and hesitation.
Then it occurred to me that it was likely the TPS.  I opened the connector and gave it a shot of contact cleaner.  Did a ride yesterday and it ran clean and strong
Never wanting to miss out on a good preventative medicine tip, I also sprayed some Deoxit on my TPS connection. For the first time I noticed that little open gap at the front of the TPS and body as shown in the attached photo. I'm assuming this is by design, but seems to be a place water can easily enter. Any thoughts on why this gap exists?c6dd6c8fa870ddfef1a3b63585612986.jpg

Sent from my SM-S901U using Tapatalk

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12 minutes ago, 4corsa said:

Never wanting to miss out on a good preventative medicine tip, I also sprayed some Deoxit on my TPS connection. For the first time I noticed that little open gap at the front of the TPS and body as shown in the attached photo. I'm assuming this is by design, but seems to be a place water can easily enter. Any thoughts on why this gap exists?c6dd6c8fa870ddfef1a3b63585612986.jpg

Sent from my SM-S901U using Tapatalk
 

It's there to makes us nuts. :blink: At least we'll have a reason. Some people are nuts and nobody knows why . . .

When this was discussed before, I put a little silicone across there to keep water out. Pretty sure it just makes the TPS harder to adjust and any water that gets in there will just cook out at operating temperature. The TPS is not open under there, so is not exposed and cannot be sprayed with cleaner or DeOxit.

I did put some corrosion inhibitor on the upper throttle body shaft and its retainer at the last TPS change.

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57 minutes ago, docc said:

It's there to makes us nuts. :blink: At least we'll have a reason. Some people are nuts and nobody knows why . . .

When this was discussed before, I put a little silicone across there to keep water out. Pretty sure it just makes the TPS harder to adjust and any water that gets in there will just cook out at operating temperature. The TPS is not open under there, so is not exposed and cannot be sprayed with cleaner or DeOxit.

I did put some corrosion inhibitor on the upper throttle body shaft and its retainer at the last TPS change.

This got me thinking. The conventional wisdom has been that the TPS cannot be sprayed/treated/cleaned, but that referred to when it is attached, in place.

I'm experimenting with my old TPS on the bench and can get Caig DeOxit past the grey rotational part.  Not sure if it gets to the "wiper" . . .

(Trying to discern if the progression of resistance can be affected.)

IMG_9885.jpg

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