Is this a TPS problem?

[Goodman4]

I just got back from a trip on the FJR riding around CO, NM, AZ and UT with my nephew on his S10. It's the first long trip of any kind I've taken on the FJR in 3 or more years. My wife and I were riding the wing on all our long trips before our accident a year ago and the MT10 replaced the twisty solo rides. But the FJR is now re-promoted to my touring bike.

To the point... I had an intermittent issue with the FJR that happened a few years ago. It was on a trip with the wife to MO and after an hour on the road on a hot day it started stumbling on the highway at about 70 mph. It did it a few times and I talked to my service guy and did some forum posts. The most likely culprits were determined to be bad gas or TPS. It seemed to get better so I wrote it off, but realistically I probably haven't ridden the FJR over an hour at a time since then. I have only gotten it out for short local rides until this trip, favoring the MT.

As soon as I had been on the bike an hour last week it started stumbling again. It feels like it's trying to buck me off. It stuttered so bad as I got into Springfield MO, that I had to start pulling over in traffic, but it recovered before I got stopped. I refreshed myself on the TPS issue and was able to twist the throttle a couple times out of gear and have the problem go away for a good while. I NOW know how to do the diagnostics and read the output from the TPS and look for deadspots, but didn't in the ride. I would just jerk the throttle and be good for another long while. It stumbled after an hour on the road near the 70 mph range in 5th every day except the last when we were on 550 where the temp was in the low 50's. Also we had a few stops in the mountains, so maybe we didn't go for an hour without stopping that day. It's never exact though. Another indicator - we were booking it for a long time on 98, 89 and 89A to the North Rim and NEVER had any stumbles with the throttle twisted higher. It only would try to buck me off at mid-throttle which I think indicates a corroded spot on the TPS. The only part that doesn't make sense is the 1 hour in when it's hot and doesn't do it until then.

When I had my service guy check it out three years ago, it didn't come up with errors, because he doesn't ride it an hour. My service guy is great but the guy at the service desk doesn't know what a TPS is and couldn't find the part in the book to give me a price (It's listed as Speed Sensor in the Yammi catalogue, not Throttle Position Sensor from what I can tell). From what I describe, do you feel it's worth me just telling him to order one and replace it? Or does the 1 hour / temp thing make you doubt the TPS?

I suppose I could get time in a couple weeks to ride an hour and be ready to do the diag right then on the road. What da ya think?

 

[RossKean]

It might help to know what model year. There were TPS recalls for Gen I. Few issues with Gen II. Quite a few problems with Gen III. Especially the early years. Symptoms are consistent with TPS, but could be anything from an intermittent battery connection to a funky fuel pump.

 

[Whooshka]

According to his sig line it's a 2007.

More importantly since the codes could be accessed, what codes came up? I thought they get stored until cleared. When was the last time it had fresh plugs, filters, etc? Sounds like it might be the hose to the MAP sensor getting gunked up? And I'd check all the vacuum lines.

 

[RossKean]

According to his sig line it's a 2007.

More importantly since the codes could be accessed, what codes came up? I thought they get stored until cleared. When was the last time it had fresh plugs, filters, etc? Sounds like it might be the hose to the MAP sensor getting gunked up? And I'd check all the vacuum lines.

I was browsing on my phone and I don't see the sig line...
The gunked MAP sensor line gives a #14 fault code. Easy enough to retrieve the code and easy to remedy.

Edit: This was my MAP sensor odyssey -
https://www.fjrforum.com/threads/fault-code-14-gen-ii-solved.170314/

 

[Mihalis fjr]

It sounds to me like a defective TPS but and a defective fuel pump can cause a like this symptom..Both TPS and fuel pump they appear their problem especially when they get warm/hot..TPS is the N.18 on the throttle body.
https://www.partzilla.com/product/yamaha/3P6-85885-00-00

 

[art miller]

My first 2007 FJR had a similar issue. It happened in upper elevations. It was referred to as altitude sickness. On the road reedy was wack the throttle a couple times and it would clear up. My second 2007 had a Commander III installed and I never had an issue with stumble at any elevation.

 

[Goodman4]

Yep, it's a 2007. I have not had ANY diag failure codes. I guess I got the TPS diag process from another site. Here it is:

- hold select and reset while turning key on for 5-10 seconds.
- release both buttons
- press both again and after 2-3 seconds the display shows d1:01 and a two digit number
- the two digit number is the reading of the TPS and should increment up as you twist the throttle

IF I have the corrosion spot in the mid-section like others have said, when it is stumbling it will drop to a low number in the bad spot for a position or two. Since this respected group is not 100% agreeing it is TPS, I will force myself to take a long ride on a warm day and get the problem to appear then stop immediately and go through the diag process above. I won't take it to the shop until I have seen this problem in the diag.

Thanks for the advice.

 

[Mihalis fjr]

Yep, it's a 2007. I have not had ANY diag failure codes. I guess I got the TPS diag process from another site. Here it is:

- hold select and reset while turning key on for 5-10 seconds.
- release both buttons
- press both again and after 2-3 seconds the display shows d1:01 and a two digit number
- the two digit number is the reading of the TPS and should increment up as you twist the throttle

IF I have the corrosion spot in the mid-section like others have said, when it is stumbling it will drop to a low number in the bad spot for a position or two. Since this respected group is not 100% agreeing it is TPS, I will force myself to take a long ride on a warm day and get the problem to appear then stop immediately and go through the diag process above. I won't take it to the shop until I have seen this problem in the diag.

Thanks for the advice.

Unfortunately,in the most cases of a defective TPS the diag process didn't found that it was defective...We waiting about from your...

 

[rbentnail]

Unfortunately,in the most cases of a defective TPS the diag process didn't found that it was defective...We waiting about from your...

Exactly! Time and again owners have insisted there's nothing wrong with the TPS only to find out that replacing it solved the problem.

 

[Brodie]

As described to me, many years ago by a Yamaha engineer at one of the motorcycle shows, the altitude problem worked like this: The ECU triggers a barometric reading at startup, which sets the black box mapping. If this happens in the lower elevations, and is rode into the mountains with the throttle not being opened past 1/4 turn, it will not take another sample. The young engineers could not duplicate the issue because they rode it like a sport bike. Once they talked to several old(er) guys who were experiencing this issue, the engineers figured it out. The owners were taking a leisurely ride, most likely with their lady on the back, and never got on the throttle past 1/4 turn; the bike running like crap at altitude. They went back and rode their test bikes like an old man, and were finally able to have it happen to them. I believe the fix was a re-program of the ECU, and the early 2nd Generation bikes had a recall for it.

Hope this helps.

Brodie

 

[FJR Flyer]

Yeah, from the parts diagram for 2007:

THROTTLE SENSOR 3P6-85885-00-00​

My Gen III TPS issue was that the throttle got very jerky, minor stumbling. The GEN III OBD codes didn't make any sense. Replaced the TPS and all was good.