Throttle Position Sensor Screws

[raesewell]

Hi all, I've had a problem with the throttle being a bit jerky on low revs after a lot of searching and working I think I've narrowed it down to the TPS. I changed the plugs and did a Throttle Body Balance and the problem was still there. I have heard tell that the TPS can develop a fault. So my question is, is there an easy way to access the awkward screw on a 2013 bike on the TPS.

Would it be feasible to get it off any way possible and use an ordinary bolt?

 

[roger dodger]

I just did the deed (w/ the help of an FJR tech session)(thanks NBB). I bought the T25 security bit, raised the tank and the TPS is easily visible on the left side of the TB. Getting the 2 screws out was ok (1 easy, 1 tricky)... but putting them back is the challenge. Put the easy screw in to hold the TPS. For the tricky screw we used grease on the tip of the bit to hold them together, and a long needle nose pliers to turn the bit (very) slowly. It all worked out (w/ a few drops ) and on to the calibration.

In Diag mode 1, rotate the TPS to see 15 @ idle, 100 @ WFO.... and set the screws tight. Re-check and test drive ...it was 'good as new'! So nice to have my Fast Jet Rocket back to 'smooth as a babies bottom' again.

 

[raesewell]

I'll have to take another look at it, there didn't seem to be enough room to get a 25mm T25 in there.

 

[NBB]

It not 25mm.

The T25 security bit (Torx) is a 6 sided star screw looking. The security portion is a hole in the center of the driver bit.

Here are some good images. https://www.ebay.co.uk/itm/7pc-Hollow-Security-Torx-Bit-Set-CT3706-T9-T10-T15-T20-T25-T27-T30-Freepost-/231955200989

rd you are welcome, hope to see you on the road sometime.

 

[raesewell]

25mm is the length of the T25 bit unless there are shorter ones I don't know about.

Oh bye the way it's very unlikely you will see me on the road as I live in the UK

 

[Eagle Six]

This response has nothing helpful to your question (roger dodger has already done that), just a comment. I haven't replaced my TPS as yet, but it probably needs replacing or adjustment. I have reset it three times and the reset works well, takes a minute, no tools. Key on, no start, rotate throttle slow from idle to full, and back to idle, then again to full and back to idle, then key off. Key on and start. Each time I did this there was an immediate improvement, and with about 10 miles of riding, the throttle was back to smooth. When I do the diag test, mine shows 17 at idle (within range), and 101 at full throttle (that is 1 above high range). It's my understanding, when performing the diag test is that when rotating the throttle from idle to full and back again, very slowly, that the numbers incline and decline steady without skipping any numbers, which is what mine does.

The first time I experienced the jerky throttle condition (I call it whiskey throttle syndrome), I had started the bike cold and shut it off within a few seconds. The second time, I started cold, it ran for about a minute and I inadvertently went to 1st gear before retracting the sidestand. The third time I was climbing some hills at highway speed (this may not have anything to do with it), although this time the jerkiness wasn't near as bad as the previous two. I'm trying to hold off replacing the TPS until I have other work in that area, such as a TBS.

 

[NBB]

25mm is the length of the T25 bit unless there are shorter ones I don't know about.Oh bye the way it's very unlikely you will see me on the road as I live in the UK

I missed 25mm as the length sorry.

I was the one assisting Roger getting the screws started. Try pulling out the side of the fairing just a little to get some additional clearance. Start the back screw first and snug it to finger tight. We added a thick grease to the bit as this helped hold the screw when positioning to the front mounting hole. Follow Rogers instructions above to complete.

Good luck, we only dropped the screw twice (even with the grease) before getting it to start properly.

And the ride mention was to rd --> rodger doger

NBB

 

[raesewell]

There is a thick bit of wiring loom in the way, how did you get around that?

 

[raesewell]

I managed to push, prod and fenagle a torx T25 key into the space available and got off the TPS and gave it a twist and a squirt of contact cleaner, I need to get out and ride it now to see if it has done the trick. If it hasn't done the trick I might have to get a new TPS because the old one might be past cleaning and twisting.

If I put a new one on and the problem is still there I will be seriously disappointed.

 

[raesewell]

An Update, I took off the TPS gave it a few squirts of contact cleaner and moved it through the full range of movement and now it's as smooth as babies bums.

It's a joy to ride again. Problem solved.

 

[RossKean]

An Update, I took off the TPS gave it a few squirts of contact cleaner and moved it through the full range of movement and now it's as smooth as babies bums.It's a joy to ride again. Problem solved.

Based upon the postmortem that was done on a previously failed TPS, I suspect your issues will gradually return. It was more an issue of worn resistive tracks in the device than dirty surfaces/wipers.

 

[raesewell]

If it does return I will know where to look, diagnosing the problem is sometimes the hardest part. If it happens again I'll just replace it.

 

[Uncle Hud]

https://www.fjrforum.com/forum//index.php/topic/169700-anatomy-of-gen-iii-fly-by-wire-tps/

 

[Fred W]

The "reset" procedure described above is a placebo, more than anything actual resetting. The ECU in these bikes does not learn anything. It isn't sophisticated enough to perform adaptation like an automotive ECU does. Well, at least not up until the OBD3 additions made in 2016. Not sure about after that.

The TPS problems when they happen on this or most any other fuel injected bike are as a result of inconsistent electrical contact of the spring loaded wiper across the resistive track inside the sensor. By exercising the sensor wiper back and forth, or by shooting contact cleaner inside it, you may be able to temporarily restore conductivity, but the problem will return.

If you have already gone through these steps and seen a dramatic change after only exercising the sensor or using contact cleaner, your diagnosis is complete. I'd be buying the TPS and replacing it prophylactically rather than waiting for it to crap out at the least convenient time.

YMMV

 

[raesewell]

I might well order one Fred and have it to hand. Another thing to note, here in the United Kingdom the TPS costs £159 and to get it shipped to the UK from Partshark it's £122 including the shipping costs. If I were a UK Yamaha dealer I would be asking Yamaha some bloody awkward questions about pricing policy.

So Partshark here I come

 

[Wizard37]

I just changed the Throttle Positions Sensor (TPS) at 89000 miles. 2007 FJR, TPS is on the right side of the bike. The final indicator was the hypersensitivity closing the throttle and finally the check engine light coming on. The air pressure sensor tubes also became blocked which made things interesting with the TPS going as well.

On the Saturday the bike was performing well having just put on a set of Road Pilot 4 GT’s. I ran 180 miles on mixed roads including interstate. The next day it started, coughed, spat and ran intermittent and the engine light came on. After warming up it was still not happy, a restart and no engine light. I took it for a trip around the block. It got worse (no shit Sherlock), I had to hold 2000rpm when stopped to avoid the engine stopping. Close the throttle and it would die. The fuel gauge was dropping with a 15 mpg instant showing at times.

Once home I consulted the manual and the forum. The TPS looked a good candidate based on behavior. Thanks to the posts with very descriptive narrative. The diagnostic codes 14 indicated the air pressure sensor which I replaced last year! The voltage readout from the TPS in the diagnostic screen did not indicate any skipping but a digital readout is difficult to gauge any anomalies, I don’t have a analog volt meter with a needle and scale.

I noted the position of the attachment screws on he TPS and decided against removing the engine from the frame. A T-15 hex bit, a ratcheting 1/4” wrench and two small o-rings to put on either side on the hex to hold the bit in place, and it fits.

The air sensor lines were effectively blocked, I used a 50ml syringe to suck through from the sensor position which cleared the blockage, from blocked to totally open, could see what it was.

With the new TPS installed, the codes cleared, it is a new bike. The TPS was obviously the main issue. Now the throttle is smooth, slowing down is not a power on to power off as it was before.

Now I can see that the signs of the TPS failing were present for the last 10,000 miles at least. The sensitivity of engine braking with throttle position became very slowly worse. I had been compensating for it but it hadn’t reached the point of consciousness, just beginning to annoy. I think if another FJR owner had ridden it there would have been some discussion.

Thanks to the Forum for being a resource for diagnosing weird shit.

 

[Bill Lumberg]

Mine (gen III) went from a barely perceptible hitch to making the bike unrideable. After half a year, Yamaha replaced. Tech and moral support here was priceless. I cannot say enough about the caliber of a lot of the folks here.

I’m just settling into gear position sensor failure. I’m going the fjrforum tech route even though the bike is under warranty. Smarter and faster technical advice.

Merry Christmas.