2014 Stumble on accel.

[Bill Lumberg]

Yep. I wanted to hold out and avail myself of the intangibles I thought I was buying in late '14 (reliability and warranty support). Since they do not appear to have actually been part of the purchase, I think accepting reality and doing things like I would with my BMW (buying the part smart dudes tell me is the likely cause, and paying for it and install out of pocket), is a more productive plan than just seething. I like to ride. Far and often. I think I'll choose the most direct route to that.

 

[Mr_Canoehead]

Out of curiosity, where is the TPS on the 2014? I doubt it is on the Throttle Bodies since the bike is RBW. More likely it is near the handlebar.

 

[TownsendsFJR1300]

Whats somewhat odd, my Yamaha F150(HP) 4 stroke out board engine had a stalling problem at low idle/docking. It was a known issue on the OB forum I frequent.

It was still under warranty and instead of tweeking the TPS, TB's, (special procedure) etc, mama Yamaha paid for the entire throttle body assembly, (two, 2 barrel bodies with one sync adjuster between both TB butterfly shafts). The sync, idle set is way more difficult than on the FJR and there's actually a new tech bulletin on how to do it..

About $1,100 for it plus labor(still under warranty). It ran better for a little bit, then the idle dropped again. Had the mechanic try to raise the idle just a bit. I watched him, with a single screw driver, tune an awful vibration into the engine, which he couldn't fix.

Found a Master Tech at another marina and he was able to fix it, NO new parts,

Point, and I missed it earlier, the throttle body assembly was delivered within 5 days...

 

[TownsendsFJR1300]

Out of curiosity, where is the TPS on the 2014? I doubt it is on the Throttle Bodies since the bike is RBW. More likely it is near the handlebar.

Part #12, left side of the bike...

https://www.partzilla.com/parts/search/Yamaha/Motorcycle/2014/FJR1300A+-+FJR13AER/INTAKE+2/parts.html

 

[wheatonFJR]

Why not just replace the TPS now. Easy to do and the part should be available. May or may not fix your issue but it's a lot faster then waiting till the cows come home!

Yeah! Demand at least that...should be able to get that part...which is the important one anyways. Shows them yer being "reasonable".

 

[ionbeam]

Out of curiosity, where is the TPS on the 2014? I doubt it is on the Throttle Bodies since the bike is RBW. More likely it is near the handlebar.

Part #12, left side of the bike...

https://www.partzilla.com/parts/search/Yamaha/Motorcycle/2014/FJR1300A+-+FJR13AER/INTAKE+2/parts.html

Also, take note of item 21, Accelerator Sensor. Your problem is "stumble on accel" Hmmm...... It sure makes a feller want to see the Data Log for both the Accelerator Sensor and TPS. It would almost lead one to believe that a non-wear-out item like the TB rack isn't the true root cause even though the attached sensors will likely fix your problems once it (eventually) gets here off the slow boat (and then hand carried from San Diego to Ga).

There is a shaft that runs through all the throttle bodies that the throttle plates attach to, the TPS has a slotted opening that fits over the end of the shaft so that the TPS is in locked sync with throttle plate movement.

Edit to add: FSM is at home, I'll check to see if the Accelerator sensor has a DIAG readout. Bet it does. The Accelerator and Throttle Position Sensors are adjustable and should be in agreement with each other.

Edit: Accelerator position sensor DIAG 14 to test; Fault Code 59 for 'stuck at' type failure Range displayed on the Data Display: throttle fully closed 12 - 22; throttle fully open 97 - 109

 

[Mr_Canoehead]

Interesting - sounds like we are talking about two sensors.

On most vehicles that are Drive By Wire the throttle pedal position sensor TPPS is used to measure the demand from the driver. Then there is a throttle position sensor that feeds back actual position to the ECU. The fiche shows that the FJR still uses throttle cables from the grip to the carb area - what do they connect to? That could be the function of part 21.

 

[ionbeam]

[speculation]

A rider twists the Go-Fast tube on the handlebars. The throttle cables turn the Accelerator Position Sensor which tells the ECU both how far and how fast the throttle has been actuated. The ECU reads the engine monitoring sensors, does a bunch of math plus uses look-up tables and then sends a set of signals, one goes to the Fuel Injectors, another to the Throttle Servo to open the throttle plates while monitoring the TPS to see that the Throttle Servo responded accurately, and then, in the ECU's spare time it sends correctly timed ignition signals

[/speculation]

While updating the dash information including tach and speedo, monitoring the ABS and ESU (ES only, of course) and monitoring the controls on the handlebars and meter assembly and driving the signaling system which no longer uses a flasher module.

 

[Fred W]

Yeah this ^^^

It's a little counter-intuitive to have a twist grip operating push and pull cables that go all the way down to a sending unit near the throttle body, but that is exactly what they have designed.

 

[mcatrophy]

Yeah this ^^^
It's a little counter-intuitive to have a twist grip operating push and pull cables that go all the way down to a sending unit near the throttle body, but that is exactly what they have designed.

There may be a legal requirement to have positive closing of the throttle bodies by the "return" cable, does it have any mechanical connection to the throttle shaft?
When I was young, there was only a go-faster cable with a spring return. The law later required the return cable so the rider could force the throttle shut if all else failed (broken spring, seized bearings or whatever).

Actually, when I was young, my Tiger Cub had a "go-not-quite-so-slowly" cable. But still fast enough to bring me to the notice of The Law on occasion .

 

[TownsendsFJR1300]

Well, here's the throttle pull and push cables. I don't where it attaches to, if even the TB...

https://www.partzilla.com/parts/search/Yamaha/Motorcycle/2014/FJR1300A+-+FJR13AER/STEERING+HANDLE+CABLE/parts.html

Great catch Ionbeam, Didn't see (or look for) the accelerator sensor...

 

[Fred W]

The throttle cables attach only to the accelerator position sensor. The sensor signal goes to the ECU and the ECU sends out a control signal to the servo motor that actually moves the throttle plate linkage. As far as I know there is no mechanical connection between the throttle cables and the throttle linkage, which is the entire point of "throttle by wire."

That's why I said it was a counter-intuitive design. The accelerator position sensor could have been located up on the right handlebar so that no push pull cables were required at all.

 

[TownsendsFJR1300]

The throttle cables attach only to the accelerator position sensor. The sensor signal goes to the ECU and the ECU sends out a control signal to the servo motor that actually moves the throttle plate linkage. As far as I know there is no mechanical connection between the throttle cables and the throttle linkage, which is the entire point of "throttle by wire."
That's why I said it was a counter-intuitive design. The accelerator position sensor could have been located up on the right handlebar so that no push pull cables were required at all.

Thanks... A bunch of extra electrical stuff, STILL WITH CABLES, that really does nothing but add to the complexity of the system..

IMO, absolutely silly, just more stuff to break..

 

[Constant Mesh]

When the throttle by wire system was introduced on the 2006 R6 there was a mechanical connection between the cable mechanism and the throttle valves. You could force the valves closed with the throttle grip.

You can see the mechanical linkage in this drawing.

https://www.yamaha-motor.eu/designcafe/en/about-design/technology/index.aspx?view=article&id=442635

Don't know if that linkage was carried over to the '13+ FJR?

Part #19 on the parts diagram shown earlier is a switch. Since it's a switch it may be indicating the position of the throttle valves -- are they closed? This switch appears to be located near the cable mechanism. Maybe this switch is used to shut down the cruise when you close the throttle grip?

I'd guess there is a mechanical linkage between the cable assembly and the throttle valves. Maybe you need a fail safe which can override the throttle servo and close the throttle if it goes wacky? Probably better than hitting the kill switch.

 

[mcatrophy]

When the throttle by wire system was introduced on the 2006 R6 there was a mechanical connection between the cable mechanism and the throttle valves. You could force the valves closed with the throttle grip.
You can see the mechanical linkage in this drawing.

https://www.yamaha-motor.eu/designcafe/en/about-design/technology/index.aspx?view=article&id=442635

Don't know if that linkage was carried over to the '13+ FJR?

Part #19 on the parts diagram shown earlier is a switch. Since it's a switch it may be indicating the position of the throttle valves -- are they closed? This switch appears to be located near the cable mechanism. Maybe this switch is used to shut down the cruise when you close the throttle grip?

I'd guess there is a mechanical linkage between the cable assembly and the throttle valves. Maybe you need a fail safe which can override the throttle servo and close the throttle if it goes wacky? Probably better than hitting the kill switch.

There is a switch to disable the cruise control on the FJR G3, operated by pushing the throttle tube beyond closed, I suspect that is this switch - does the R6 have CC? (G*d - I'm ignorant )

 

[Bill Lumberg]

Very interesting stuff.

 

[TownsendsFJR1300]

I'm betting that accelerator sensor / switch is the culprit...

I don't remember seeing it on any earlier FJR's (Fairly new part for smoother acceleration?)

 

[ionbeam]

Very interesting stuff.

But, basically useless to ya.

The throttle cables attach to a pulley system which is attached under the throttle bodies in a metal frame where previous Gen's had the TPS. This provides the connection to the Accelerator Sensor and looks much like the older Gen's pulley system. There is no direct connection to the throttle plates, the throttle cable attachment point is below the throttle plate shaft. The spring loaded assembly that the throttle cable attaches to has non-adjustable throttle movement stops for idle and WOT. There is a switch which resides on the throttle plate shaft which Yamaha clearly identifies as SWITCH which I can only guess may be related to a safety item, the signal goes straight to the ECU(1). More research needed.

Grip Cancel Switch. This switch is still on the mechanical side of the throttle control and can be activated no matter what is happening to the electronic side of the throttle control.

To adjust the Acceleration Sensor -- "First remove the Throttle Bodies..."

(1) The switched side goes directly to the ECU. The power for the switch starts at the Cruise Control fuse and goes through the Clutch switch, Front Brake switch and Rear Brake switch.

 

[Constant Mesh]

This video describes the troubleshooting of the throttle by wire system.



At the 2:40 mark of the video you can see the tech opening the throttle valves with the linkage from the throttle grip/cable assembly.

Also at the 4:38 mark you can see how the servo motor can move the linkage between the throttle valves and throttle cable assembly. I don't know if it's actually turning the grip too but it may be. As the cruise control operates does it turn the grip?

It's interesting that the throttle position and accelerator sensors are both 4 wire components. Apparently there are two separate wiper variable resistance devices in each of the sensors. There is redundancy it appears.

 

[Fred W]

I'm betting that accelerator sensor / switch is the culprit...
I don't remember seeing it on any earlier FJR's (Fairly new part for smoother acceleration?)

Yes and No. The accelerator sensor is what you are turning with the twist grip (via the push pull cables). It then sends a proportional signal equal to how far you have turned the throttle grip to the ECU. This is the "command" part of the fly by wire. There is a small servo motor on the throttle bodies that is connected to the throttle plate linkage. The ECU sends a proportional signal to the servo motor for how open it wants the throttle to be. On the opposite end of the throttle is the TPS which gives the ECU feedback as to how far the throttle is actually open at any moment.

The ECU is in complete control of the throttle plates. Your hand on the throttle is just a suggestion to the ECU of where you would like it to be, but the ECU can either do what you ask or set the throttle to where it thinks it should be. All of this is what makes up "Fly by Wire", which is what facilitates electronic cruise control, traction control, and automated idle speed adjustment (both cold and warm).

As has been mentioned the switch is just to cancel cruise control when you turn the grip backwards.