Sporadically won't hold idle.

[puppychow]

Fired up the bike this morning and it idled fine as the fast idle was going. First stop light I came to less than 50 yards from my house, as I rolled to a stop - the bike shut off.

I thought I stalled it, so clicked the start button and it would catch, fire up and then just die again, did this a couple of times before it caught and held idle and I was able to ride off..a little worried at the time.

I went through several stop lights out of town and it wasn't dying, so I rode it 150 miles on the freeway without issue and as I exit and am coming into another town...I rolled to the stop light and came to a full stop - bike shuts off again. I hit the starter and it fires right back up.

Then I roll to a stop in the turn lane trying to make a left at the next light and it shuts off again and this time it would start but won't hold idle even after 5 tries and then the 6th try it revs back into life and I make the turn into a parking lot and it shuts off again, 2 more tries and then it idles and I could park it.

I wait about 10-15 minutes and then it idles just fine and I can't replicate the problem again, so I rode to a friend's house and still no problem and I go through a couple stops. I pull into his garage and 5 minutes later we start and restart the bike several times while it is still warm from my ride and the problem won't reproduce itself.

I am worried though that this damn issue will strand me in the middle of bumfuck nowhere..because it is so sporadic and random in nature.

Any ideas?? I am going to do a TBS as soon as I can next week, will probably have to wait till next Friday/Saturday, don't have time during weekdays ..

Any other ideas other than TBS? Can't be the fast idle can it? If so, why doesn't it do it all the time I slow down to a stop when the bike is already hot/warm?

At a loss here..

 

[Harald]

What's your normal warm engine idle speed set at?

I've had a similar problem when my idle was set at about 900. Bumped it up to 1100 and haven't had a problem since.

 

[puppychow]

Its already at 1100. I will check again tomorrow, maybe up it a bit anyway?

 

[RsvlFeej]

Puppychow,

The common factor in your story is you're coming to a stop whenever the problem manifests, so not completely random (although it doesn't happen at every stop) - maybe you're intermittently losing a connection (ignition switch or battery?) as you brake. I'd think electrical first... unless you're convinced it's fuel-related.

Good luck,

RsvlFeej

 

[puppychow]

OK So.

#1 Play with idle speed settings (bump up perhaps).

#2 Check battery terminal connections.

#3 How do you check ignition switch integrity?

#4 TBS, but that won't be till a few days..

 

[Fred W]

You said this only happens when the bike is still fairly cold, right? Not when first starting but a few minutes afterwards before the engine is fully warmed up.

Sounds like your fast idle is too low, or it is coming off fast idle too quickly. There is an adjustment screw to raise the fast idle. It is buried underneath the throttle bodies. Howie documented where it is in one of his old posts I'd expect to see the bike idle at 2000-2500 rpm on first cold start.

If it is already idling high enough when started cold then it may be that the wax motor that drives the fast idle mechanism (like a thermostat) is not working right.

 

[puppychow]

No. not only when the bike is fairly cold. For example, it did the same after riding 150 miles on the freeway in 95 degree heat. I took the exit and the first stop which was 2-3 minutes afterwards after riding through a 30mph zone, it shut itself off. Bike was showing 4 bars on the temp gauge at that time. So it's doing it both when fairly cold and fairly hot, but then again not all the time.

It's sporadic and not always reproducible, maybe it will get more reproducible as time goes on..

I will start the bike when it is cold this morning and note the fast idle speed and then wait for it to warm up and note the warm idle, I remember it was 1100 or so yesterday, but I will give the idle screw a bump up anyway and see if that does anything at all..

Thanks for all the suggestions so far!

To do so far:

#1 Play with idle speed settings (Note fast idle speed, and then warm idle speed, bump up perhaps).

#2 Check battery terminal connections.

#3 How do you check ignition switch integrity?

#4 Check Spark Plug cables and spark plug seating.

#5 Check for missing vacuum caps.

#6 TBS, but that won't be till a few days..

 

[ionbeam]

It sounds like the problem is brought on when the engine goes into the decel fuel cut-off. Have you had the TPS replaced? I see your tag line sports the Timex logo, was it fixed?

 

[puppychow]

According to Roseville Yamaha a few years ago when the bike was in for service the TPS was replaced as per recall according to records related to the VIN (but not by them). Ticker was also fixed tens of thousands of miles ago, no problems since - till just now. Bike is due for another valve check in another 8K miles or so. (26 x 3 = 78K - it has 70K on it now).

This is how to Check TPS sensor?

Checking the TPS Sensor

This test is done using the Diagnostic screen. How to:

With the key off, press and hold the "Select" and "Reset" buttons simultaneously and turn the key on (do not start, just ON), continue to hold the buttons until the display next to the fuel gauge says diAG (5-10 seconds).

Release the two buttons. Now, press the "Select" and "Reset" buttons simultaneously again. After ~ 2 seconds the display should show d1:01 on top and a two digit number at the bottom. You are now looking at the throttle position sensor (TPS) output. The TPS value is the two digits at the bottom of the display.

Turning the throttle will change the digits. Normal is 15-17 with the throttle closed and 97 to 100 with the throttle wide open. When the TPS goes bad it can be catastrophic, where the two digit value is just plain wrong and doesn't follow the throttle at all. This could be the TPS, it could be in the harness that connects to the TPS or it could be the ECU.

The other failure mode of the TPS is to have 'dead spots' as the throttle is opened. This is the most common failure and it usually occurs at roughly 20-40% of throttle opening because that is range where the throttle is positioned for most riding. To check this -- very, very slowly open the throttle from full closed to full open and observe that the numbers climb with no skipped numbers and no drop-out readings (e.g. 45, 46, 47, 01, 01, 48, 49) The 01 reading is a 'drop-out'. This failure is almost certainly the TPS.

To leave the diAG mode simply turn the key off. Done.

 

[puppychow]

I found this - sounds like it is the TPS!

https://www.fjrforum.com/forum//index.php?showtopic=13158&hl=

2003: https://motorcycles.a...recalls020n.htm
2004: https://motorcycles.a...recalls057d.htm
2005: https://motorcycles.a...recalls055k.htm

All read the same: THANKS TO DEAN WOODWARD, MICAPEAK MAILING LIST

Defect Summary:

On certain motorcycles, an improperly designed throttle position
sensor could cause an intermittently unstable idle when the engine is at
idling speed when the motorcycle is stopped or during low-speed
operations. The engine could stall as a result.

Consequence Summary:

If the engine stalls after the operator disengages the clutch in a
low gear while riding, the rear tire might slip momentarily if the
operator abruptly re-engages the clutch. This could result in a crash
with injury or death.

Corrective Summary:

Dealers will replace the throttle position sensor free of charge.
The recall is expected to begin on October 11, 2006. Owners may contact
Yamaha at 1-888-88-yamaha.

Affected VINs:
2003 FJR1300R/RC All
2004 FJR1300S/SC/AS/ASC All
2005 FJR1300T RP07E-0002237-0003981
2005 FJR1300TC RP07Y-0000400-0000661
2005 FJR1300AT RP09E-0000873-0002293
2005 FJRI300ATC RP09Y-0000181-0000510

 

[ionbeam]

A long while ago I was chasing driveability issues, the following is excerpted from the troubleshooting post. Along the way I found that the TPS can *always* test good with the engine off but fail with the engine running.

<excerpt>

Next --- > Even though the TPS has worked in all previous testing I couldn't rule it out. At this point I had a faint recollection that the problem suddenly became worse after taking all the play out of the throttle cable. Hmmm... I pulled the connector, checked voltages, ohmed the unit at ambient temps and cleaned the filthy sensor. All normal. I back-probed the connector, ran wires up to the dash and Velcroed my cheapie DMM to the dash and went for a ride with Good Pillion™ installed (3). Three bars, fan cycled on, 35 mph BUCK, FART, MISFIRE. Whoa baby, did you see what the DMM showed?!?! Next glitch, DMM showed a major TPS drop-out. By this point I note that the drop-outs always occur between .775 and .778 volts. I could ride anyplace around that particular range and had no problems. Deliberate operation in that range caused TPS drop out and the beginnings of Pillion hammering on my helmet to stop doing that. Back in the driveway I checked my light throttle problem at idle and it was plain to see the TPS drop out. As soon as everything cooled a bit the TPS worked normally again.

</excerpt>

 

[puppychow]

Thank you!

I think a call to my dealer is in order as soon as they open and I will confirm that the records show that the TPS was indeed replaced a long time ago. If so, this would be a replaced TPS which is failing again and will need to be replaced.

PITA to DIY? I keep reading of the second torx screw being a pain to get out.. still searching for a good write-up with pictures..

 

[puppychow]

This be it..

https://www.fjrforum.com/forum/index.php?showtopic=10755

 

[puppychow]

Checked the TPS readings on the Diag screen. 16 throttle full OFF, 99 throttle full ON.

Going to order a replacement TPS today. It seems like part numbers have been replaced once again with a 3P6 prefix now..according to partshark.com

 

[dcarver]

Good mojo to yah, PuppyC! Sounds like you're on the right track.

 

[Fred W]

When the TPS went TU on my Vstrom (essentially the same TPS is used on those 'zookies) it was only intermittently acting up after a thorough heat soaking. Like running for an hour or more on the highway, then pull off at the exit and fart, belch, stall. When this would happen, the trick to getting her going again was to euther wait for it to cool down, or else rotate the throttler aggressively 8 or 10 times with the key turned off. The idea here is the wipoer of the TPS isn't making good electrical contact and you want to try and "clean" the track it wipes across.

After a few of the above scenarios progressed to the point that it started to buck and fart while the throttle was still open, while riding on the highway, as long as the engine heat was high enough. It was definitely exacerbated by the heat.

 

[ionbeam]

To supplement what Fred said, the TPS will have a small dead spot, moving the throttle just a little bit can put you back into a functional spot on the TPS resistor path. Graphic pictures that show the problem HERE.

 

[puppychow]

Wow Fred it was like you were reading the bike's mind on my ride back home today from my friend's. Made it home but an hour or so on the highway later, the bike would want to shut off with the clutch pulled in and the throttle completely off no matter what speed.

Also, gas mileage shot to hell, 140 miles in and gas gauge starts to flash, this usually doesn't happen till 210-215 miles or so.

Nursed it to a gas station and at every stop light or stop had to give it gas while stopped to keep it above 1k or it would do its best to die. Which it did just as I pulled up to the pump, then would not start and hold idle, for several tried until I turned ignition off, turned it back on and then it was like back to normal, like nothing happened.

I was only 10 minutes away from home at this point and no issues all the way home for that 10 minute ride..

 

[puppychow]

Another data point previous TPS readings I took were when the bike was totally cold as in having sat overnight. Those readings on the Diag screen were 16, full OFF, 99 full ON.

Diag reading on TPS 10 minutes after getting home.

12 full OFF and rising as the bike cools.

94 full ON and rising as the bike cools..

Fascinating and makes complete sense considering ionbeams explanation as to how heat makes them transition from resistive to non-resistive!!

You guys are geniuses!!