Just a couple things I’d sure like to know

[1911]

Just a couple things I’d sure like to know:

If you have a Gen2, such as my 2007, that DOESN’T run very poorly at minimal throttle openings, what does these measurements look like?

Bike on center stand, trans in neutral, engine running-

At idle-vacuum in inches/hg?

Vacuum at 3000 RPM steady?

MAP voltage under the same conditions?

At steady 3000 does your O2 fluctuate nicely from well above to well below 450mv?

When you transition from “key on engine off” to “engine running” do you lose .1 volt on your 5 volt reference circuit?

Granted, no normal person with a good running bike would be measuring this stuff but on the slim chance that somebody has worked through driveability issues and took a note or two…..

Heaven knows that I’ll have a lot more knowledge about what FJR electrons do by the time I get this thing fixed.

Vacuum measurements taken teed into the MAP sensor hose 1 inch from sensor and voltages backprobed + at ECU and meter grounded to battery neg.

This bike’s had the ECU recall done and a Brodie ground harness installed. TPS looks good and consistent. The MAP sensor plumbing is CLEAN.

 

[08FJR4ME]

Just ride,

Dave

 

[philter]

I assume you are speaking English, but Mechanics English or Electronics English. LOL

The only thing I have to offer to this discussion is that, as you know, I have an 07 as well and it is always available for you to compare to yours; Heck, I might learn something.

 

[RossKean]

Same bike, same location. Sounds like its worth getting together for some side-by-side measurements (and a beer)!

 

[1911]

The only thing I have to offer to this discussion is that, as you know, I have an 07 as well and it is always available for you to compare to yours; Heck, I might learn something.

^^^^^^^BINGO^^^^^^

I don't know how much you'd learn but you'd sure get a lunch or dinner out of it.

 

[08FJR4ME]

So what's the issue? Is the bike a nanosecond slower now in a quarter mile? Are you trying minimize the amount of electron loss so you can add one more set of auxiliary lights?

Let's get right to the point.

Thanks, Dave

 

[Knifemaker]

Um, if it ain't broke...don't fix it?

OCD?

What was the question again?

 

[1911]

So what's the issue? Is the bike a nanosecond slower now in a quarter mile? Are you trying minimize the amount of electron loss so you can add one more set of auxiliary lights?

Let's get right to the point.

Thanks, Dave

This forum went offline right in the middle of this discussion. I sure am glad it's back. We also worked on this in another sandbox. 

The issue:

The problem is a bad misfire at minimal throttle opening. Could also be described as a lean surge or off-idle stumble. Trying to maintain a steady 45 to 65 MPH on level ground results in a bucking bronc experience and rolling through a sweeper with a little power isn’t possible. The bike idles just fine and above about 25 % throttle everything is well too. I would have bet a cross-country ride on a stock seat that the TPS was bad but it measures good at the start and the voltage climbs smoothly.

The bike has 90k on it and all but 4 of those are mine. The problem has just come on in the last 600 miles. The only mods are a K&N filter., G2 throttle tube and a little bump up with the Barbarian Jumper Mod. The last valve check and TB sync was about 10k ago. A couple exhaust clearances were near minimum so I was planning on reshimming this winter. No error codes. The plugs look pretty normal and even.

In the misfire zone (bike stationary) I can manipulate the MAP voltage by a couple hundred millivolts and the misfire will go away and O2 voltage will come off the lean side. All this may be moot because I’m not REALLY duplicating the on road failure with the bike on the centerstand, as real as it may seem. Comparing stationary measurements to known-good values is the only way to satisfy certain curiosities right now. We could end up with a couple DVOMs taped to the tank as we ride down the road

And an update:

Watching TPS, measued at the ECU, key on engine off, as I wiggle the injector harness

 https://www.youtube.com/watch?v=MrfEmWduJFY

 

[08FJR4ME]

Purchase the below and your problems will be solved. I had a stumbling issue on the 08 and after adding the PC3 it went away. Good luck Dave

https://www.revzilla.com/motorcycle/dynojet-pcfc-fuel-controller-yamaha-fjr1300-2006-2012?utm_source=bing&utm_medium=cse&utm_campaign=PLA-Dynojet-Products&utm_id=bing_73550678_1339205168761208_77103308199158_pla-4587299950644964_c&utm_term=4587299950644964&msclkid=522211819aae1475ed984c0facfee1c3

 

[1911]

Purchase the below and your problems will be solved. I had a stumbling issue on the 08 and after adding the PC3 it went away. Good luck Dave

https://www.revzilla.com/motorcycle/dynojet-pcfc-fuel-controller-yamaha-fjr1300-2006-2012?utm_source=bing&utm_medium=cse&utm_campaign=PLA-Dynojet-Products&utm_id=bing_73550678_1339205168761208_77103308199158_pla-4587299950644964_c&utm_term=4587299950644964&msclkid=522211819aae1475ed984c0facfee1c3

I don't see how that will fix the broken wire between the TPS and ECU.

 

[RossKean]

An aftermarket "fix" with a fuelling controller isn't the answer.  It used to work and now doesn't.

Did you get together with philter to compare bikes?

Did you check for any stored fault codes?  14 is MAP related and can cause some serious running issues - especially at low throttle openings.

 

[1911]

this should have been in a new post back in sept 2019 instead of being edited into an old post in the middle of the thread:

And an update:

Watching TPS, measued at the ECU, key on engine off, as I wiggle the injector harness

 https://www.youtube.com/watch?v=MrfEmWduJFY

 

[Dan S]

this should have been in a new post back in sept 2019 instead of being edited into an old post in the middle of the thread:

And an update:

Watching TPS, measued at the ECU, key on engine off, as I wiggle the injector harness

 https://www.youtube.com/watch?v=MrfEmWduJFY

so did a repair of the TPS wire fix your problem?

 

[1911]

so did a repair of the TPS wire fix your problem?

Yes