CO Adjustments

[03HiYoSilver]

Joe,

What an interesting diagnosis you have there.

When I had similar problems, Erratic Idle/Fouling #4, this is when I looked at all the Electronic Connections for Shorts/Contamination...this is when I found the Main Harness Corrosion problem that fixed about 90% of the problem.In these connections there is contacts to the Coils/Injectors/ECU,etc.

Here's the link to the GenI Diagram:

https://www.fjrforum.com/forum//index.php?showtopic=22734&st=0&p=268059entry268059

I am wondering if your GenII Spiders (since you don't have a Main Harness Connector) may be Corroding or Starting to Fail... with these ever so inconsistant problems?

Ultimately, my Trottlebody Assy. was found to be defective which was causing #4 Cylinder to hardly modulate and was yielding a 2400 HC levels compared to the Normal 300 Range. This was found after we installed the RivNuts to the headers and was able to identify the CO/HC levels from each Cylinder.

Just some food for thought with your process....

 

[Fred W]

I have a 2007. When you guys talk about the surging between 1000-3000, what exactly does it feel like? I've always had a snatchy problem. For instance, when going through corners, I will down shift, and when I get back on the throttle, there is a sudden jerk. Or, today I was going into a left hand turn fairly fast. I downshifted to 3rd, and let the clutch out going into the turn. So 3rd gear, clutch out, no throttle, coasting into the turn. As I entered the turn, I rolled back on the throttle, and got a sudden jerk. I've always called it herky jerky.

I did the throttle spring unwind, and it doesn't even touch the tang anymore. So, the herky jerky that I'm describing is the surging, or do I have something else? Also, if I hammer the throttle between 1000-3000 it usually acts like it's struggling, but as soon as I get over 3000rpm it gets very smooth, and takes off.

Thanks, Lucas

Hi Lucas.

What you are describing is exactly what I'm trying to cure. I need to finish diagnosing it first though.

Joe

Actually, what you guys are talking about is NOT the surging issue. It is the snatchy throttle problem, or what I call the "off to on throttle transition" abruptness. This is the issue that I was trying to cure by adding fuel in the zero throttle column of the PCIII fuel map (when I made ionbeam remark about my stinky exhaust). My theory was that the fuel injection was cutting off fuel on engine over-run (ie when the throttle is closed and you are coasting through higher rpm ranges), and that when you then opened the throttle it would suddenly begin to add fuel and you went from negative to positive thrust abruptly. Note that, when I did do this, and created the stinky exhaust, it did seem to cure the snatchiness. Clearly, if Joe's observation that the idle fueling is too rich is true, then there is more investigation needed to fully understand what is happening here.

Surging is a different beast altogether, and seems to afflict primarily the 1st gens, as the 2nd gens run off different ECU programs. It also seems to vary somewhat from bike to bike, although it might just be varying rider sensitivity to its occurrence.

Surging happens only at steady, low throttle conditions, and seems worst at relatively low rpms (below 5k rpm). These would be the conditions when you are cruising along and holding a steady speed. It feels like a slight random, but continuous acceleration and deceleration that makes the bike feel like it is surging forward.

I've felt this phenomenon on several other bikes I've owned (1994 BMW R1100RS, 2001 Concours, 2001 Triumph Trophy, and my 05 FJR) and to me it is very annoying. It occurs because the manufacturers have set up the fueling on these bikes to run too lean for minimum emissions and maximum mileage. In every case, just slightly enrichening the mixture under these low throttle conditions eliminates the surging entirely. On the carb bikes it meant putting in one size large pilot jet and/or adjusting the pilot circuit screw. On FI bikes it means either installing the barbarian mod and upping the CO settings at idle or using a PCIII.

And then there is the burbling at idle, which they all seem to do. It sure would be nice to have a steadier idle for aesthetic reasons, but I could live with the lumpy idle and call it a "characteristic" of the beast if the other two issues are mitigated.

 

[Donal]

I have a 2009 and I had the stumbling symtoms exactly as Fred described. No need to do the Barbarian mod over here, we have direct access to the ECU. Changed all my CO settings to +15 (they were all 0) and it transformed the bike. Now it will roll along happily at less than 30 MPH in 5th gear and will pick up without hesitation from there. YMMV

Don

 

[Denver_FJR]

I have a 2007. When you guys talk about the surging between 1000-3000, what exactly does it feel like? I've always had a snatchy problem. For instance, when going through corners, I will down shift, and when I get back on the throttle, there is a sudden jerk. Or, today I was going into a left hand turn fairly fast. I downshifted to 3rd, and let the clutch out going into the turn. So 3rd gear, clutch out, no throttle, coasting into the turn. As I entered the turn, I rolled back on the throttle, and got a sudden jerk. I've always called it herky jerky.

I did the throttle spring unwind, and it doesn't even touch the tang anymore. So, the herky jerky that I'm describing is the surging, or do I have something else? Also, if I hammer the throttle between 1000-3000 it usually acts like it's struggling, but as soon as I get over 3000rpm it gets very smooth, and takes off.

Thanks, Lucas

The cure for these scenarios is not tweaking the CO via BJM or PCM III, but rather not fully cutting throttle in these situations. Maintaining throttle at about 1700 ~ 2000 RPM while downshifting will make your downshifts and transitions back to thrust smooth as butter.

Last year I also tried bumping up CO (hey, all the cool kids are doing it) but recently set it back. The change didn't do anything for smoothness or other throttle characteristics and bike was leaving a a rotten egg smell in garage after each ride. No gas analyzer here but my interpretation was changing CO was making bike run too rich.

 

[Fred W]

The cure for these scenarios is not tweaking the CO via BJM or PCM III, but rather not fully cutting throttle in these situations. Maintaining throttle at about 1700 ~ 2000 RPM while downshifting will make your downshifts and transitions back to thrust smooth as butter.

That's not a cure. That's a work around.

Yes, you can try to avoid that and things will be smoother.

There will always be some times when you have to cut throttle completely and then come back onto it. On carbureted bikes the off to on throttle transition is smooth because the carburetor continues to supply a small amount of fuel under trailing throttle. On Fuel injected bikes they have programmed it to cut the fueling entirely under those conditions, so essentially the fire in the engine goes out. THen when you crack the throttle back open even a tiny bit, boom she fires back up.

Last year I also tried bumping up CO (hey, all the cool kids are doing it) but recently set it back. The change didn't do anything for smoothness or other throttle characteristics and bike was leaving a a rotten egg smell in garage after each ride. No gas analyzer here but my interpretation was changing CO was making bike run too rich.

The problem with bumping up CO is that it has the greatest effect at idle and a dimishing effect at increased rpm and throttle openings. It also doesn't do anything about the ECU cutting the fuel off on trailing throttle. I was also unsuccessful at improving my bike's driveability using the CO settings. I could increase the setting to the point of an obviously too rich condition and the lean stumbling at 2500-4000 rpm continued.

The PCIII allows far more flexibility as to where you'll be adding the fuel. I'm not sure it is the end-all be-all some folks think it is, but is can be used to get rid of some of the fueling issues in these bikes. Combine that with better corner throttle control as you suggest and you'd be a real smooth rider.

 

[ionbeam]

There will always be some times when you have to cut throttle completely and then come back onto it. On carbureted bikes the off to on throttle transition is smooth because the carburetor continues to supply a small amount of fuel under trailing throttle. On Fuel injected bikes they have programmed it to cut the fueling entirely under those conditions, so essentially the fire in the engine goes out. THen when you crack the throttle back open even a tiny bit, boom she fires back up...It also doesn't do anything about the ECU cutting the fuel off on trailing throttle.

I did some digging back to 2006 to find some things I posted about abrupt throttle. Straight from the FSM:

In the second chart, note the acceleration transition between FI segments E and F.

The reason it feels like fuel was abruptly cut off is because it was. Then when you roll the throttle back on the the ECU does not immediately resume FI, the ECU has a small delay. By the time FI resumes you may have rolled the throttle several degrees and that causes the FI to be abrupt and more than what you intended.

Some of my related FI fossils from the past --

When Yamaha was dabbling with fuel injection ~2002 they knew that there were some issues with throttle abruptness. The 2002 R1 injection rack retained vacuum slides to smooth throttle response (refer to Yamaha Parts for a view). The FI abruptness was discussed by many motorcycle magazines like this (2011 -- the article is now dead so I eliminated the link.)

FWIW, the surging is related to meeting emissions beyond 2008 causing leanness just off idle to ~3k RPM, but doesn't seem to effect all bikes the same amount. The decel fuel cut-off is real, it is explained in the FSM. All bikes must have the decel abruptness to some degree (heck, it's built in). Things like drive-line slop and spark timing variations can contribute to making decel either prominent of passive. Throttle springs are the same for everyone, engine smoothness issues along with individual needs and perceptions will cause this to range from no issue to major issue. Throttle ratio is primarily a Gen II thing. The mechanics are the same for everyone so it is an individual needs and perception issue.
The ECU is pretty harsh in the way it handles FI mapping during acel and decel, I'm not sure much can be done for smoothness without addressing the mapping. Just to throw something out here... When I was doing some troubleshooting I put a vacuum gauge on the vacuum signal to the fuel pressure regulator and got quite an unexpected surprise. With the spring/diaphragm of the vacuum gauge dampening the rate of vacuum change at the FPR it took a great deal of the sting out of the abrupt acel/decel. I rode with the vacuum gauge attached for several days and almost left it permanently installed

In terms of engine smoothness issues there is surging -- light loads, lower throttle settings; engine abruptness -- decel fuel cut-off and sudden reactivation of FI; throttle control 1 -- trying to maintain smooth operation while dealing with the previous mentioned engine smoothness items as well as strong throttle return springs; throttle control 2 -- the ratio of grip rotation to throttle pulley movement, effecting rate of throttle plate movement. Another role player is spark timing for retard/advance. Spark remapping doesn't seem to be available for the FJR engine management system (at least so far). Boy would I *love* to have spark mapping as part of a PCIII program.
The barbarian jumper/CO mod lets you manage engine heat and light load surging in a narrow, one dimensional way. The PCIII helps all of the engine smoothness issues in more of a 3D way. The G2 at the grip end of the throttle cable and FredShims™ at the throttle pulley address the mechanical throttle control. The springie-thingie which neuters spring tension addresses some of the throttle control problems.

The major parts of diagnosing the surging are to determine if the ECU is getting incorrect or inexact data; if all the parts of the FI and ignition circuits respond as directed by the ECU. If the controls and actuators are working and all of the above is 'nominal' then the ECU is making bad decisions -- software. [opinion]Yamaha did not install a data port like OBDII. Bad. Very bad. If they had, a dealer would be able to see that was going on. Big mistake.[/opinion]
In lower gears, when making small throttle transitions my FI feels like it goes into the decel mode too deeply then makes up for it by applying accel to strongly. When entering corners this causes the RPMs to drop too low, too fast then recover too strong. I subconsciously compensate these days but if I pay attention to it and observe, it is quite noticeable. I strongly feel that the issue with my bike is that the software is not applying the decel and accel modes correctly for my particular motor/drive train. I would bet that a very minor software tweak to reduce a accel/decel sensitivity factor would smooth out my bike. In the FSM, under Features, read the Acceleration Enrichment and the Deceleration Fuel Cut-off.

 

[joebiodiesel]

Actually, what you guys are talking about is NOT the surging issue. It is the snatchy throttle problem, or what I call the "off to on throttle transition" abruptness. This is the issue that I was trying to cure by adding fuel in the zero throttle column of the PCIII fuel map (when I made ionbeam remark about my stinky exhaust). My theory was that the fuel injection was cutting off fuel on engine over-run (ie when the throttle is closed and you are coasting through higher rpm ranges), and that when you then opened the throttle it would suddenly begin to add fuel and you went from negative to positive thrust abruptly. Note that, when I did do this, and created the stinky exhaust, it did seem to cure the snatchiness. Clearly, if Joe's observation that the idle fueling is too rich is true, then there is more investigation needed to fully understand what is happening here.

Surging is a different beast altogether, and seems to afflict primarily the 1st gens, as the 2nd gens run off different ECU programs. It also seems to vary somewhat from bike to bike, although it might just be varying rider sensitivity to its occurrence.

Surging happens only at steady, low throttle conditions, and seems worst at relatively low rpms (below 5k rpm). These would be the conditions when you are cruising along and holding a steady speed. It feels like a slight random, but continuous acceleration and deceleration that makes the bike feel like it is surging forward.

I've felt this phenomenon on several other bikes I've owned (1994 BMW R1100RS, 2001 Concours, 2001 Triumph Trophy, and my 05 FJR) and to me it is very annoying. It occurs because the manufacturers have set up the fueling on these bikes to run too lean for minimum emissions and maximum mileage. In every case, just slightly enrichening the mixture under these low throttle conditions eliminates the surging entirely. On the carb bikes it meant putting in one size large pilot jet and/or adjusting the pilot circuit screw. On FI bikes it means either installing the barbarian mod and upping the CO settings at idle or using a PCIII.

And then there is the burbling at idle, which they all seem to do. It sure would be nice to have a steadier idle for aesthetic reasons, but I could live with the lumpy idle and call it a "characteristic" of the beast if the other two issues are mitigated.

My bike does 3 things I'm not happy with, but I believe they are all fuel related.

Idles rough. The engine is rich when this is happening.

Surges at steady throttle between 1000-3000 RPMs. The surge cycles steadily at a rate of twice every 5 seconds or so. It will do this as long as the throttle is held steady, and the engine is very lean while doing this.

Has a hesitation when opening the thottle at low RPMs. Probably a result of the lean mixture, but a gas bench is not fast enough to catch a problem like this. I will address the lean surge first and see what happens with hesitation.

Joe

 

[Crash Cash]

When Yamaha was dabbling with fuel injection ~2002 they knew that there were some issues with throttle abruptness. The 2002 R1 injection rack retained vacuum slides to smooth throttle response (refer to Yamaha Parts for a view).

FWIW, Suzuki deals with this using their SDTV system, where they have a 2nd computer controlled throttle plate above the rider-operated one. It opens more slowly, and keeps the airflow from going too lean for the FI to handle when the rider honks the throttle open. This would act just like the R1 vacuum slides.

I also think race bikes add a 2nd showerhead injector so that they can suddenly add enough fuel to cope with the huge increase in airflow.

Does that make any sense? Of course, it's not something we can retrofit. Plus I'm kind of surprised people are running in the 1000-2000rpm range when they're not sitting at a light. I seem to never be below 2800, myself. I guess that's why I've never noticed any such problems.

 

[Fred W]

[Plus I'm kind of surprised people are running in the 1000-2000rpm range when they're not sitting at a light. I seem to never be below 2800, myself. I guess that's why I've never noticed any such problems.

The lean surging on 1st gens is not limited to 1000 to 2000 rpm. I'm not sure where that idea came from. It will occur on 1st gen bikes running at a steady throttle opening at almost any rpm. You feel it more in lower gears and at lower rpms because the hunting is a larger percentage of the total rpm, but without a PCIII, mine surges considerably at 3500 -4000 rpm in any gear. Like you, I seldom find myself below 3000 rpm. 4k is the sweet spot for cruising along at 50 mph in 3rd gear, 60 mph in 4th gear or 70 mph in 5th gear.

The phenomenon of deceleration fuel cut-off and the subsequent jerky off to on throttle transition is definitely not limited to any particular rpm.

 

[joebiodiesel]

I got to fool around with the bike a littel more today. I learned a few more interesting things.

While not part of the diagnosis, I noticed that the FJR adds enrichment with asynchronous pulses, and widely varied injection pulses. What that means in english, is that rather than simply turning the injectors for a longer period of time, they add extra pulses of fuel along with longer injection pulses. I didn't expext it on the FJR, as primitive as the injection system is.

Asynchronous pulse. It does it more often during times of enrichment. Early 80s GMs also did Asynchronous pulses at idle.

Widely varied pulses at idle.

The following stuff IS related to the diagnosis.

These graphs are of the TPS Voltage and Injector Pulse Width. Notice that as the TPS calls for enrichment the PCM increases increases it in steps insteady of doing it smoothly. This leads me to believe there are not that many fuel cell blocks. This is easily repeated.

TPS is green. Inj Pulse Width in mS is in yellow.

The second step was to graph the same info while it is acting up. Here is what is going on while it is doing the low load/low RPM surge. Note the cycling of the injection pulses while the TPS is steady. MAP was also steady while this was happening. Sorry, no screen shot.

Also observed, the O2 sensor responds VERY slowly. My gas bench os almost faster! :blink:

The O2 only cycles at a highway cruise, and reads rich most any other time except decel. It is slow enough that you really can't use it to diagnose the fuel problem I'm having.

I'm betting if I get the fuel mixture a bit richer while it is surging it will settle things down a bit.

Time for a PCIII.

Joe

PS: I know this topic has been beaten to death on this forum. If I'm boring you....sorry...kinda.

 

[Fred W]

Actually, although this has been discussed a lot, I can't recall seeing the scope plots that go with it. I think that, as is often the case, pictures such as these are valuable to increasing understanding. IOW, keep it up!!

So, in plot #3, you were just lightly blipping the throttle (to vary the TPS), right? Was it really 5 times in 2 seconds? Or is that time base wrong somehow? And yes, I would say that the scope shows the granularity of the FJR fuel map there. But this is to relatively small changes in throttle, right? I'd imagine that there are a whole lot more steps above the few seen there.

In that last plot, don't you think it is likely that the ECU is varying the injection pulse width based on the O2 sensor's feedback? I wonder if you would have the same thing with the O2 disconnected.

 

[Donal]

Definitely not boring to me. As you say this topic has been discussed ad nauseam but it has always been a matter of opinions as opposed to real data. Keep it coming - love it :clapping: :clapping: :clapping:

Don

 

[joebiodiesel]

Actually, although this has been discussed a lot, I can't recall seeing the scope plots that go with it. I think that, as is often the case, pictures such as these are valuable to increasing understanding. IOW, keep it up!!

So, in plot #3, you were just lightly blipping the throttle (to vary the TPS), right? Was it really 5 times in 2 seconds? Or is that time base wrong somehow? And yes, I would say that the scope shows the granularity of the FJR fuel map there. But this is to relatively small changes in throttle, right? I'd imagine that there are a whole lot more steps above the few seen there.

In that last plot, don't you think it is likely that the ECU is varying the injection pulse width based on the O2 sensor's feedback? I wonder if you would have the same thing with the O2 disconnected.

Good catch on the timebase error. It is the software that I am using to view the recorded files. It's definitely buggy.

The elapsed time is around 30 seconds. The software goofs up when I change zoom levels. Sorry about that. I didn't see it until you pointed it out.

Before I ever put a scope or gas bench on the bike I thought it had a biased O2 sensor. It happens on cars sometimes. The O2 reads a little bit rich, the PCM leans out the mixture a little bit and you end up with a surge that follows the O2 cycle rate. That is not happening here. The O2 dives lean and stays there while it is surging. It takes about 20 seconds for the O2 to respond anyway. I can't believe it reacts so slowly. I'm wondering if it's bad, but I'm not going to replace it until I can check another bike.

You are right about there being a lot more fuel cells than the ones shown here. I was making very small throttle blips, as you noted. I was still surprised at how crude it appears though.

Here is what the MAP/TPS did during the low RPM surge. Note that the throttle openings are low, and the O2 (in yellow this time) starts to drop off, reading lean. It never cycles. Also note that the O2 is on a 5V scale, so it moves a lot less in this shot.

Thanks for the feedback. I appreciate it, and could use the extra insite as I screw around with this.

 

[joebiodiesel]

Any chance an Admin can let me back in my post to note the time bases are incorrect? ....or can do it themselves?

 

[Denver_FJR]

Doesn't the FJR use a narrow band O2 sensor, and if so, shouldn't its output be fluctuating between rich and lean output?

 

[joebiodiesel]

Doesn't the FJR use a narrow band O2 sensor, and if so, shouldn't its output be fluctuating between rich and lean output?

Yes. Narrow band.

I would expect it to fluctuate all the time, but it only did it after extended cruise at highway speeds. You had to cruise for 2 or 3 minutes before the O2 started to cycle, and if you interrupted it by going to full throttle, or decel, it would take a minute or two to begin cycling again. Definitely doesn't act like a car does.

O2 cycling:

 

[Bounce]

excellent thread! thanks!

 

[dlfunk]

I'm glad I found this thread because my FJR has been driving me nuts. Its a 2005 I bought used a year and a half ago. Unfortunately a lot of my riding is in city traffic where I experience the 1500-2000rpm sluggishness/burbling a lot. I hear exhaust popping at idle and up to 5000rpm. Its really bad just under 2000rpm, which is also where the surging/hesitation/rpm hunting is the worst, but I can hear slight popping at all rpm's if the engine isn't under load and the throttle input is constant. Is the popping I hear normal lean stuff and coincident with the surging others have commented on? One dealer said "these big I-4s don't like low rpms" and the other said "they all do that". I did the Barbarian/CO mod to no effect, cleaned wiring harness that can cause problems, TBS, etc., but to no avail. Am I just experiencing the normal GenI FJR behavior, and if so does a PCIII take care of most of it? I would gladly pay $300 for a PCIII (or a lot more, dammit!) if it fixed a bike that's otherwise the exact bike I was meant to be with! Basically I just want to know if what I'm experiencing is common and can be fixed.

 

[03HiYoSilver]

I did the Barbarian/CO mod to no effect, cleaned wiring harness that can cause problems, TBS, etc., but to no avail.

Am I just experiencing the normal GenI FJR behavior,

NO

DL,

Have you Checked out your Main Connector? This solved my problem and others and don't need a PCIII.

https://www.fjrforum.com/forum//index.php?s=&showtopic=22734&view=findpost&p=268059

Rad's Post on Symptoms https://www.fjrforum.com/forum//index.php?s=&showtopic=105232&view=findpost&p=450507

As far as the Popping goes, you can get rid of the P.A.I.R. System.

Then I would do a THOROUGH TBS again... I did the UnAuthorized one and it really smoothed things out.

Hope this helps...

 

[dlfunk]

I did the Barbarian/CO mod to no effect, cleaned wiring harness that can cause problems, TBS, etc., but to no avail.

Am I just experiencing the normal GenI FJR behavior,

DL,

Have you Checked out your Main Connector? This solved my problem and others and don't need a PCIII.

https://www.fjrforum.com/forum//index.php?s=&showtopic=22734&view=findpost&p=268059

Rad's Post on Symptoms https://www.fjrforum.com/forum//index.php?s=&showtopic=105232&view=findpost&p=450507

As far as the Popping goes, you can get rid of the P.A.I.R. System.

Then I would do a THOROUGH TBS again... I did the UnAuthorized one and it really smoothed things out.

Hope this helps...

Thanks HiYo. I misspoke. I cleaned the main connector (not harness). I saw a little corrosion but cleaned and greased. I haven't done the unauthorized TBS. I haven't removed the PAIR. I guess I was a little worried about removing stuff in case I wanted to sell it (seriously, I don't think I'll sell this bike). But if that takes away the popping at all rpm's I will do it right now. Its annoying. Really I just want to get rid of that sub-2000rpm roughness and popping at basically all rpm's.