'13 "Jolene" Has Developed a Throttle Surge at 45-55mph

[Viper_Dad]

Jolene's had a good life. Not the easiest life, she's kissed the asphalt a few times, but she's my gorgeous girl and I want her running perfectly. My last two rides I've started experiencing a mild surge between 45-55mph. It was especially noticeable last Monday when I rode the Blue Ridge Parkway (speed limit = 45mph). Holding the throttle steady, I could feel the bike surging slightly, moving back and forth underneath me. Nothing noticeable to others, nothing crazy with the tachometer, just a slight bucking bronco feeling until I rolled into the throttle a bit. The throttle is otherwise very responsive (who doesn't LOVE second gear, right?!) and I can't duplicate it at other speed ranges but I've experienced it now in both Touring and Sport mode. Jolene is a 2013 Gen III with no modifications to her engine, I love her just the way Yamaha made her. She currently has 68,000+ miles and the throttle bodies were synced at 60K. I believe 1911 has dealt with this, so maybe he can lend some insight but I appreciate any input you FJR wizards can offer.

I should note that although I'm not extremely gifted as a mechanic, I have a Festus. Everyone should have a Festus. I bet if I buy some cinnamon buns he'd help me sort this out over the winter. After all, he loves Jolene as much as I do.

[raYzerman]

My standard advice... if the bike sits for 10 days or more (with ethanol fuel), put an ounce or two of Seafoam in the tank in case there is moisture separating in the fuel... alternate, an ounce of Isopropanol. Elliminate water as an issue.
You could check the vacuum lines/nipple on the MAP sensor......
http://www.fjriders.com/forums/viewtopi ... =19&t=4614
Assumption.... the sparkie plugs are recent and fine......
Next we're kinda pointing to checking the TPS..... nice instructions from Alan (if I can find that thread).... if the issue is at a certain throttle opening...
try this one first.
http://www.fjriders.com/forums/viewtopi ... 190#p99190

Quoting ionbeam's instructions.....
"... there is no need to guess about the TPS. Back-probe the TPS connector. Black DMM lead on the Black/Blue wire and the red DMM lead on the Yellow signal wire. At idle read .63 to .73 volts. Don't sweat a few milli-volts if it out of range. The way the TPS is attached to the main throttle body shaft the TPS idle voltage reading will change if you adjust the idle speed using the manual adjuster on the right side frame area. The ECU is mostly looking at throttle rate of change and span of throttle change instead of absolute voltage. If the TPS is bad in a narrow portion of the resistive track the ECU will see the sudden drop as a fast throttle change and will chop the FI off via the decel fuel cutoff and then when past the resistive track defect the ECU will see the sudden voltage rise like the rider is pinning the throttle wide open for a brief second and it's this rapid off/on that the ECU sees that makes the engine run so rough or outright stall.

Leave the meter back-probed to the TPS, Velcro/rubber band the meter to your handlebars and for a ride until it heats up. When the off idle misfire happens watch the meter. If it's the TPS, the voltage on the meter will notch down dramatically then come back up as you get the throttle beyond the (potentially) damaged spot inside the TPS. Steady, linear voltage = good TPS = look elsewhere.

The ECU provides +5 volt reference to most sensors and uses an isolated ground from the ECU so it is best to ground the meter to the Black/Blue wire and not chassis or battery ground."

[Intech]

You don't happen to see the neutral light flicker a little when it does this do you? There is a a relay in the nose that the fuel pump goes through along with the neutral light. I had the same symptoms,but with the neutral light. Changing that relay corrected it for me. Powerman was having the same symptoms and removed the relay to find a good bit of corrosion. Cleaned it up and reinstalled and problem gone. Have to look at the parts fiche to get the number.

[Intech]

I believe this is the relay: 5VK-81950-30-00

Item 25 on the Electrical-2 fiche

I would pull it and check for corrosion.

[wheatonFJR]

You don't happen to see the neutral light flicker a little when it does this do you? There is a a relay in the nose that the fuel pump goes through along with the neutral light. I had the same symptoms,but with the neutral light. Changing that relay corrected it for me. Powerman was having the same symptoms and removed the relay to find a good bit of corrosion. Cleaned it up and reinstalled and problem gone. Have to look at the parts fiche to get the number.

Yeah, VD....have your Festus get right on that.

[bigjohnsd]

When were the plugs last changed?
Lean surge can often be attributed to spark plugs that aren't firing properly due to increased high voltage demand.

[Festus]

Plugs were changed at about 54,000 miles, which is when the TB's were synched. No flashing neutral light that I've heard him mention.

Looks like we'll check the TBS voltage and see what she's up to.

She's probably tired of spending her whole life riding around in "T" mode.

[raYzerman]

IF it were me, I'd make sure there was a dozen baker's dozen of cinnamon buns before I started.......

[Festus]

IF it were me, I'd make sure there was a dozen baker's dozen of cinnamon buns before I started.......

...and not those cheap convenience store cinnamon buns either. Little Debby ain't gonna cut it. It's going to take cinnamon buns that would send a diabetic to the hospital.

[Road Runner]

I don't think it's fuel or it would do it more often. The Ethanol is already 10% alcohol so I wouldn't add more. Maybe a vacuum leak. Or maybe a TPS but not likely.
I'm thinking just shift into 3rd and no more issue.

[Hppants]

I do believe that in some respects, a good warm cinnamon bun can make a lot of bad go away....

[wheatonFJR]

IF it were me, I'd make sure there was a dozen baker's dozen of cinnamon buns before I started.......

...and not those cheap convenience store cinnamon buns either. Little Debby ain't gonna cut it. It's going to take cinnamon buns that would send a diabetic to the hospital.

Lil Debby would be a slap in the face...a sign of mockery.

[wheatonFJR]

I don't think it's fuel or it would do it more often. The Ethanol is already 10% alcohol so I wouldn't add more. Maybe a vacuum leak. Or maybe a TPS but not likely.
I'm thinking just shift into 3rd and no more issue.

You are MEAN, Art. Just plain mean.

[raYzerman]

I don't think it's fuel or it would do it more often. The Ethanol is already 10% alcohol so I wouldn't add more. Maybe a vacuum leak. Or maybe a TPS but not likely.
I'm thinking just shift into 3rd and no more issue.

Art is not mean.... Ethanol is quite different than isopropanol... it can only stand about 4.5% water, then when phase separation occurs and water sinks to the bottom, you have problems. Isopropanol will take care of several times more water, only need a small amount. Other alternative, drain the tank and refuel with fresh, preferably non-ethanol.

[Road Runner]

I don't think it's fuel or it would do it more often. The Ethanol is already 10% alcohol so I wouldn't add more. Maybe a vacuum leak. Or maybe a TPS but not likely.
I'm thinking just shift into 3rd and no more issue.

Art is not mean.... Ethanol is quite different than isopropanol... it can only stand about 4.5% water, then when phase separation occurs and water sinks to the bottom, you have problems. Isopropanol will take care of several times more water, only need a small amount. Other alternative, drain the tank and refuel with fresh, preferably non-ethanol.

Im not mean, just having a discussion. In 6 gallons of gas there is 10% or .6 gallons alcohol. So adding 1 more ounce of any kind of alcohol won't really do anything. I was a boat tech for years and have seen a lot of phase separation and never was able to fix it by adding alcohol. Only fix to it is empty the tank and get fresh fuel.
My .02 cents

[raYzerman]

Depending on what MSDS there's been over time, Seafoam is mostly Naptha with about 30% isopropanol.

[Intech]

Any update?

[Festus]

Any update?

Update: He hasn't done shit.

[RacinRay]

I'm betting it's the name. Jolene????
It's probably running like shit to spite you!

[Intech]

WTF viper? You can't post a problem here and get all kinds of advice and then just disappear! Do I need to come down there?