CO Adjustments

[joebiodiesel]

My bike has a slight misfire and unsteady idle, and has a surge below 3000 RPMs at very low throttle openings. I know this is not surprising to most people here, but I wanted to fool around with it.

I grabbed by 5 gas analyzer and lab scope and went to work. I was expecting it to be lean at idle, but it sure wasn't. The surge is definitely a lean surge though.

Before starting I checked the CO adjustment. The previous owner had it adjusted to around +17 or so. It was very rich at idle.

Note the high O2 reading. It is pegged at over 900mV, definitely rich.

Note the CO Readings as well. CO over 5%.

I started dropping the CO adjustment a bit at a time, but didn't seem to be making any progress at all. It had to go to negative CO numbers before I got to any reading I thought would be normal. Here is what it looked like at -25.

Active O2 sensor, but not too active. Not sure if this is normal on a FJR, as this is the first one I've spent any time with.

The gas readings confirm it is finally leaning out. The idle miss was gone, but it still surged the same when you opened the throttle. I'm not sure where I will end up with this setting. I've never seen a post of anyone running lower numbers than stock, but I know what works for me....

The lean surge between 2000-3000RPMs does not look like it will be changed with the CO setting. A PC may be in my future if I want to get rid of this. I double checked the TPS to make sure this wasn't causing my problem. It is very lean at this RPM range. It moves quickly out of it as soon as the RPMs reach 3000, so it does look like it is programming, and not some other reason, that it is doing this.

Note CO under 1%. Lean for sure. High HC and O2 is probably a result of the misfire, and not typical of a good running engine.

Joe

 

[Donal]

Very interesting - not sure I understand any of it but very interesting

Can you give a bit more detail about your set-up. I assume your 'lab scope' is some sort of PC based application. What sort of analyser do you have? :blink:

Don

 

[joebiodiesel]

The scope and gas bench are both Snap-on products. The scope is a Vantage-Pro and the gas bench is their Flexible Gas Analyzer, but being viewed with a Modis. These all run Windows CE. I like the gas bench because it is portable. It can be used going down the road. You can even add a tach probe. It records the data so you don't have to watch it while riding. I have used it to jet every recreational vehicle I own.

Joe

 

[Bounce]

Did you do your testing before the cat? Before the 4-into-2-into-1-into-2 junction?

 

[wmadoty]

Another thing to consider is fuel pressure maybe being high. Maybe a problem with the fuel pressure regulator or injector driver grounds at the ECU (spider bite). Or a vacuum leak (most likely problem in my opinion). Are the caps on the throttle body adjustment ports there? Just a thought and might help to check on those things. Upstream of the cat O2 sensors on everything should fluctuate. Downstream O2 Sensors still fluctuate but not as much.

 

[Donal]

The scope and gas bench are both Snap-on products. The scope is a Vantage-Pro and the gas bench is their Flexible Gas Analyzer, but being viewed with a Modis. These all run Windows CE. I like the gas bench because it is portable. It can be used going down the road. You can even add a tach probe. It records the data so you don't have to watch it while riding. I have used it to jet every recreational vehicle I own.

Joe

Thanks but I won't be doing this any time soon - at $2699 for the Vantage-Pro (I didn't get a price for the Flexible Gas Analyzer)

Don

 

[joebiodiesel]

Did you do your testing before the cat? Before the 4-into-2-into-1-into-2 junction?

Hi Bounce,

Yes, before the Cat.

No, next to the O2 Sensor.

Joe

 

[joebiodiesel]

Another thing to consider is fuel pressure maybe being high. Maybe a problem with the fuel pressure regulator or injector driver grounds at the ECU (spider bite). Or a vacuum leak (most likely problem in my opinion). Are the caps on the throttle body adjustment ports there? Just a thought and might help to check on those things. Upstream of the cat O2 sensors on everything should fluctuate. Downstream O2 Sensors still fluctuate but not as much.

Good ideas. I don't have an adapter to check fuel pressure. I probably ought to check it, but it leans out SO quickly when you climb above 1500 RPMs, I'm still guessing programming. Hig fuel pressure should give rich readings across the RPM range, but less at they climb....theoretically.

Throttle body caps are in place. I didn't check for a vacuum leak, but I've got a smoke machine, so that will only take a minute. Good idea to check that.

Not spider bit. I made my own harness and installed it.

I do need to check the MAP reading. It may have a low vacuum reading, and could cause some of what I've got here.

Thanks for the help. I appreciate it.

Joe

 

[joebiodiesel]

Thanks but I won't be doing this any time soon - at $2699 for the Vantage-Pro (I didn't get a price for the Flexible Gas Analyzer)

Don

The price of this stuff is definitely hard to justify for personal use. It'd be WAY cheaper to employ someone that already owned it. For the record, the FGA is a bit more than twice the price of the VP, and requires around $400.00 in sensors every year or so.

Joe

 

[Fred W]

Hi Joe,

Very interesting. So if I'm understanding your results correctly it is saying that at idle the bike is running fat, and the uneven idle is rich blubbering. Then, at some (undetermined) point it becomes overly lean, which is the low throttle opening surging we have all come to know and love(?).

I sure wish I had your gas analyzer setup as I do have the PCIII installed and have messed with the 0% throttle openings trying to ameliorate the unsteady idle (to no avail). But I was adding fuel thinking it was part of the same lean condition as the cruise stumble.

If your hypothesis is true, it doesn't make a lot of sense for Yamaha to have set them up this way (intentionally) as that wouldn't have helped them pass the emissions testing criteria.

More data. By gawd, we need more data!!

 

[Bounce]

Did you do your testing before the cat? Before the 4-into-2-into-1-into-2 junction?

Hi Bounce, Yes, before the Cat. No, next to the O2 Sensor.

i ask because it makes me wonder if knowing what each cylinder is doing would help. a bung to each exhaust pipe to read each instead of one overall reading.

 

[joebiodiesel]

i ask because it makes me wonder if knowing what each cylinder is doing would help. a bung to each exhaust pipe to read each instead of one overall reading.

I may end up doing this, but I really doubt there is that juch variation between the cylinders. If there is, then there must be something seriously wrong with the Yamaha Induction or Fuel Systems...and I have trouble believing that at the moment. When it comes to diagnosing vehicles, I'm never done being surprised though.

Joe

 

[joebiodiesel]

Hi Joe,

Very interesting. So if I'm understanding your results correctly it is saying that at idle the bike is running fat, and the uneven idle is rich blubbering. Then, at some (undetermined) point it becomes overly lean, which is the low throttle opening surging we have all come to know and love(?).

I sure wish I had your gas analyzer setup as I do have the PCIII installed and have messed with the 0% throttle openings trying to ameliorate the unsteady idle (to no avail). But I was adding fuel thinking it was part of the same lean condition as the cruise stumble.

If your hypothesis is true, it doesn't make a lot of sense for Yamaha to have set them up this way (intentionally) as that wouldn't have helped them pass the emissions testing criteria.

More data. By gawd, we need more data!!

Hi Fred,

Yes, the numbers show very rich at idle, with a real lean spot above idle that disappears abruptly at 3000 RPMs, which is the same time the surge disappears

.

If you have a PCIII, have you tried the smoothness map I've seen talked about here? I did some reading on it today in the airport, and it sounds pretty darn interesting to me. I'm definitely consdering it.

If you're ever out near Syracuse, drop me a line and we'll put your bike on the bench. I'm not putting any holes in your exhaust though! You also have to disable the AIR system or the gas readings will not make any sense....not that the ones I've taken so far make any sense.

I was hoping someone was going to point out an obvious error that I was missing, like not properly saving the CO readings before starting the bike, or something similar.

It looks like Dennis Kirk has the best pricing on PCIIIs.

Joe

 

[Fred W]

Yes, the numbers show very rich at idle, with a real lean spot above idle that disappears abruptly at 3000 RPMs, which is the same time the surge disappears

On my '05 it would surge all the way up to ~4000 rpm before installing the PC3

If you have a PCIII, have you tried the smoothness map I've seen talked about here? I did some reading on it today in the airport, and it sounds pretty darn interesting to me. I'm definitely consdering it.

Yep. I first tried the "stock" map that came with the PC3 and that seemed to help. Then I tried the Wally's Smoothness Map and it eliminated about 75% of the lean surging, but didn't go quite far enough in the low throttle opening cells (for my bike). The map that I finally settled on I got from a fellow forum member who had it made on a local dyno.

One cool thing about the map utility software that comes with the PCIII is you can load and compare each of the maps in a spreadsheet like format that has graphing function and does automatic compares giving difference maps etc. Send me a PM and I'll hook you up with the software so you can play around with it and look at each the various maps and what they are doing before you get your Power Commander.

If you're ever out near Syracuse, drop me a line and we'll put your bike on the bench. I'm not putting any holes in your exhaust though! You also have to disable the AIR system or the gas readings will not make any sense....not that the ones I've taken so far make any sense.

I already have my PAIR stuff removed (just to clean up the engine bay) , so no problems there. And with the PCIII you disconnect the O2 sensor wiring, so that could be removed and use that bung for the exhaust analysis. Maybe we can get together some day.

 

[ionbeam]

If you're ever out near Syracuse, drop me a line and we'll put your bike on the bench. I'm not putting any holes in your exhaust though! You also have to disable the AIR system or the gas readings will not make any sense....not that the ones I've taken so far make any sense.

I already have my PAIR stuff removed (just to clean up the engine bay) , so no problems there. And with the PCIII you disconnect the O2 sensor wiring, so that could be removed and use that bung for the exhaust analysis. Maybe we can get together some day.

If you guys do get together to sniff each others gasses don't keep it a secret. If you don't mind a bystander I would be interested in playing this game too.

 

[joebiodiesel]

If you guys do get together to sniff each others gasses don't keep it a secret. If you don't mind a bystander I would be interested in playing this game too.

Now....is that polite!? Is THAT how you go about getting yourself invited!? My mother was right about the things she said about motorcyclists. I didn't believe it until now.

 

[Fred W]

There is actually a little story behind Professor ionbeam's inuendo: He and Mrs 'beam and I and Mrs W end up riding together fairly often on weekends during the warmer weather. On one such occasion, after I had been leading for a while, when we later took a break he told me that he had to back off as my exhaust fumes were making him high. :blink: This was right after I had experimented with adding more fuel in the zero throttle cells of my PCIII map, trying to further smooth the off-on throttle transitions to be more like a carby bike. Needless to say I reverted back to my old settings.

But it is also quite interesting that you found your bike is already idling too rich-ly. It could very well be that I had just been going in the wrong direction!!

 

[lharrell79]

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

 

[joebiodiesel]

Hi Lucas.

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

Joe