| Author |
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Sycojomo
| | Posted on Monday, November 12, 2007 - 04:26 pm: | 
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Hello,
I am new to Buell (08 xb12scg) and to this board, and very excited to find this group. I'm having a surging issue, and greatly appreciate any help.
Specifically, when I hold a steady 3000 rpms in pretty much any gear the bike behaves as if I was lugging it, but clearly I'm not. Obviously, the lower gears cause the effect to be more pronounced. I can feel the effect anytime the engine is under 4500 rpms but it seems most pronounced at 3000. I would expect this below 1500-2000, but not 3000.
The dealer has looked at it once; spark plugs, clean fuel, and did something with the exhaust valve. Didn't help. They are putting a call in to Buell, and I'll take it back in, but this is currently my only transportation so that's a pain.
One more thing, it doesn't always surge, sometimes the riding experience is almost religious. I just can't figure out how to predict the surge days, and I am not a fan of the lurch. Thanks for your time.
Cheers. |
Sparky
| | Posted on Tuesday, November 13, 2007 - 02:37 am: |
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Within its design parameters the Buell EFI works flawlessly. However, there are things other than mechanical defects that can happen to this perfect world that can have an affect on low to medium speed driveability.
For instance, the oxygen sensor in the exhaust pipe is largely responsible for controlling air/fuel mixture around 3000 rpms and below. Do you let the bike warm up long enough so that the pipe gets good and hot? Could a short warm-up induce surging later on in the ride or a longer warm-up preclude surging?
Other sensors that affect driveability are the air intake and engine temperature sensors. So, in some ways, the EFI is tuned to the outside environment and the engine's environment. Could there be a connection to the outside air temperature so that maybe on the colder parts of the day the bike runs perfect? And maybe on hotter days it tends to surge? Or is it the other way around, surging when cold and running OK when it's hot out? Or is there no correlation?
I don't have the answers. I guess I'm trying to say be a little more aware of outside conditions, take notes, and observe if the way you are operating the bike might be having an affect on its driveability. |
Sycojomo
| | Posted on Tuesday, November 13, 2007 - 10:53 am: |
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It is interesting that you mention temperature, cause it definitely seems to run better in cold weather. I usually let the bike warm up so the pipes are at least warm, although maybe not red hot. |
Loucksgl
| | Posted on Tuesday, November 13, 2007 - 12:09 pm: |
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Just had to chime in here. I feel his pain. 08 Uly surge. Perfect 50 degrees and lower. Perfect at Mt Mitchel altitudes. Rough everywhere else |
Adoogie3
| | Posted on Tuesday, November 13, 2007 - 08:36 pm: |
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I have a 08 xb12s, had same issues they seemed to clear up after 600 miles breakin.I am glad to speek with someone that has a 08 with the new ddfi 3 system they made quite a few changes for better and worse i will be keeping a close eye on this site to address these issues that may arrise. but the bucking thats normal for a little while till you get some miles on it.im at 720mi and its running smoother every day .any other questions on the 08 s ask me ive been on the phone with techs for hours on 08 changes and have all spec changes that they dont tell you on there website.I had to pry it out of the techs mouths. |
Sycojomo
| | Posted on Tuesday, November 13, 2007 - 08:46 pm: |
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Sparky,
Inspired by your suggestion of a more scientific method, when I rode the bike earlier today I thoroughly warmed the engine at idle, and then rode for about 30 minutes on everything from country roads to the interstate. The weather at the time was 67 degrees with spotty rain.
Same problem.
Also, I previously described the problem as surging. It feels more like a pattern were the fuel mixture is correct, lean, and correct again; with each beat being roughly every half to one and a half seconds apart. Of course I have no idea if this what is actually happening.
I'll ride again in a few hours, and will run it without the longer warm up period.
Cheers. |
Loucksgl
| | Posted on Tuesday, November 13, 2007 - 09:28 pm: |
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Adoogie3 --I am very curious what you found out about the 08's. I have 08 Uly that runs rough 3000rpm and pretty much everywhere in warm weather. Like a surge. At altitude its smooth as silk. 50 degree weather and under its smooth as silk. I call it surge. It is fuel delivery I'm sure. So what did ya learn about it? Thanks in advance. Incidently, 6800 miles and surge since day one. Also think about what happens to fuel air mixture at high altitude and again at cold climate. Thanks
(Message edited by loucksgl on November 13, 2007) |
Loucksgl
| | Posted on Tuesday, November 13, 2007 - 09:34 pm: |
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Sycojomo
Wish you could run your bike over the Cherahala Skyway once just to see what it does. Bet the problem goes away at 5000 feet. |
Gotj
| | Posted on Tuesday, November 13, 2007 - 09:58 pm: |
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Gary, Since he lives in Lenoir City, maybe he will. George |
Sparky
| | Posted on Wednesday, November 14, 2007 - 02:19 am: |
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OK. I've got a theory and thinkin' out loud here, grasping at straws really. I'm looking at this dyno chart that was recently posted and seeing the wavy horsepower plot. Now, could it be that the upward and downward slopes of the acceleration curve are due to some kind of lag in the EFI's response to input from the oxygen sensor? Or is there something else happening? Maybe a dyno plot is not a good analysis tool for troubleshooting surging issues at part throttle.
Granted this curve is an '05 XB12R and not an '08 model, but EFI is EFI and both use generally the same components; only the software control algorithms are different. This Wikipedia description of narrow band O2 sensors tells a story that seems strangely like what might be causing this surging.
quote:The voltage produced by the sensor is so nonlinear with respect to oxygen concentration that it is impractical for the electronic control unit (ECU) to measure intermediate values - it merely registers "lean" or "rich", and adjusts the fuel/air mixture to keep the output of the sensor alternating equally between these two values.
This type of sensor is called 'narrow band', referring to the narrow range of fuel/air ratios to which the sensor responds. The main disadvantage of narrow band sensors is their slow response: the control unit determines the exhaust gas composition by averaging the high and low swings in the sensor's output, and this process creates an inevitable delay (this statement may be misleading - see discussion).
Does anybody know if this is the type of O2 sensor in Buell's application? Wouldn't it be great if a simple mod could be done to smoothe out its signal? I was thinking that a capacitor in parallel with the oxygen sensor might do the trick but, I don't know, maybe a better type of O2 sensor or an improved software control algorithm in the ECU is in order. |
Loucksgl
| | Posted on Wednesday, November 14, 2007 - 08:14 am: |
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Sparky
Great idea on the 02 sensor theory. Makes perfect sense too. The deficiencies of the narrow band sensor would equal the characteristics we are discussing. Only thing about it is about it is all 08 XB12 bikes would have the problem cause it would be the incorrect part. A faulty or intermittent narrow band sensor would be huge. When my bike was surging (lean-rich-lean-rich) last summer, I brought the 02 sensor up to dealer tech when he said nothings wrong with my bike. He said a 02 sensor or a temp sensor would make the Buell heave and buck. So I forgot it. The 02 sensor was a huge problem with the Motronic BMW's back in the day. But a surge identical to my Buell was the result then. But I gotta trust somebody about information and he says no. So be it. Key here is that the tech at dealer level is in discussion with the tech at Buell and if the tech at dealer gives the Buell tech incorrect data, then its a circle of confusion. I was told "don't lug the bike" and sent on my way. Not angry here; just relating the story. 02's don't cost that much and temp sensors don't either. I wish Buell would authorize the dealer tech to replace all three, but one at a time to get this ended. A cheap exploration that would equate to solution to this nasty problem and the guessing would be done. I can't believe the ECM would be faulty on so many machines. Your deduction to the 02 sensor is in line with my thinking. Interesting thing is that it appears the surging thing is rearing it head with the 08's, when all that was to have been corrected with the new, fantastic electronics.
(Message edited by loucksgl on November 14, 2007) |
Sparky
| | Posted on Wednesday, November 14, 2007 - 02:33 pm: |
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Loucksgl, thanks for your input. Do you have personal experience with a Motronic BMW and, if so, what did BMW do about it?
WRT the new electronics on the 08's, I believe the ECM processes data much faster than previous versions, which is a good thing. I would think the capability is there to do a splendid job with these sensors, if the surging problem centers around O2 sensor voltage signals.
Assuming the hardware is OK, what's left is software. Just guessing, but perhaps the software engineers at Buell may not have accounted for all the environments that users are experiencing.
So, if (surging bike's) O2 sensors would happen to test out normal and there is still surging happening under certain conditions like Sycojomo's, then Buell has the control algorithm right for some conditions, but not all. They probably need to have documented what those conditions are that lead to surging. This is where you guys that are concerned about this problem can help.
Perhaps it would be constructive to have more people post in this thread, as some have done already, what conditions cause surging and what other conditions make the riding experience "almost religious" (nice term, Sycojomo). Then, as beta testers, we would be doing Buell SW Engineering a service by providing them with more data. |
Sycojomo
| | Posted on Wednesday, November 14, 2007 - 03:30 pm: |
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Hey guys,
So I rode home late last night, and as planned didn't warm the bike up at all before starting off. Other than needing to slip to clutch a little more at the first few stop lights, I didn't notice any changes in the engine's performance. Same problem. The air was fairly warm at about 55 degrees and extremely humid with very dense fog. As I got out of town and onto some small country roads, I had to ride very slowly as there were tree branches down from the rain and wind and I couldn't see more than 40-50 feet due to the very dense fog. Perfect moment to ride in second gear at about 3000 rpms ...
I have a call in to the shop to set up another visit ... also, if I didn't mention this before, I have a service manual on order.
Cheers. |
Sycojomo
| | Posted on Wednesday, November 14, 2007 - 03:32 pm: |
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Oh, I am going to try taking the bike over the Cherohala Skyway to see what happens. Hopefully before the week is out. |
Loucksgl
| | Posted on Wednesday, November 14, 2007 - 09:18 pm: |
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Sparky --Just for the record, my Uly has been running absolutely like a champ. I'm sure its due to the heavy, damp air. More dense. Remember altitude and 45 degrees its perfect. Hot 70 degrees and dry and above--- rough operation. As for BMW motronic. BMW always has had to be a leader in innovation. Anyway, bad surge was very apparent in the newer motronic twins. I was a personal friend of (the guy) who ran the service dept at BMW Of North America. We talked extensively. Motronic was just plain wrong for that set up. In short; a sophisticated computer read all the sensors and designed a perfect fuel/air mixture of perfect quantity for combustion at the left bank. The 02 sensor read the exhaust and said "too rich" and would set the right bank up for a lean mixture by sending its input back to the motronic control. A repeat of this would occur on the next injection of fuel/air. This repetitive process is felt as a surge. As I understand it, there also existed unburned fuel in the heads and BMW designed a head and piston that would allow a total burn with the addition of duel plugs (and valve angle) change. Things cleared up with the demise of Motronic. Those affected bikes could be made to run with minimal surge if each and every fuel metering parameter, including throttle body was set and adjusted to perfection. Some were made to work ok. Many bikes would never work right. Most would work well but only temporarily. Quick explanation. More to it but not the forum. Interesting to note though. BMW would not warranty any procedures we dealers would undertake to try to help the customer. They're never wrong. |
Sarodude
| | Posted on Wednesday, November 14, 2007 - 10:27 pm: |
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Talking outta my ass - but....
Have any of you ever watched an EFI vehicle hunt around a narrowband sensor's signal in closed loop mode?
I wonder if some of the surging our efi equipped riders isn't that hunting - especially given the human feel frequency of 1 - 1.5 seconds.
Just a thought.
-Saro |
Acejay
| | Posted on Thursday, November 15, 2007 - 10:00 am: |
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my 07 bolt has the exact same problem, 3000 rpm magic mark. doesn't always happen, but when it does its mighty frustrating. usually happens in 5th on the highway. I just drop it into 4th to lift the revs and avoid the problem.
whatever the problem is it something the ddfi II and III bikes have in common. |
Sycojomo
| | Posted on Thursday, November 15, 2007 - 03:17 pm: |
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Now this interesting.
Based on my memories and the experiences of Loucksgl, I figured I would have a beautifully smooth ride today, with the air temperature currently at 42 degrees. Nope. Surging below 4000-4500, and as always, 3000 is the worst. |
Iamike
| | Posted on Thursday, November 15, 2007 - 07:55 pm: |
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On the tubers, isn't it at 3k that they switch from the map to closed loop? If the XBs are the same maybe they aren't making that switch as graceful as they should?
This is where it would be nice to play with your own setup. You could play with the setting to see if map adjustments would make any difference to the operation.
I'm curious if you guys have tried swapping parts like O2 sensors? My '99 started surging some just before one of the injectors gave up the ghost. It was unridable after that. |
Loucksgl
| | Posted on Friday, November 16, 2007 - 09:15 am: |
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Guess I'm not alone with this surging thing. My gut tells me its a sensor (eng temp, 02 etc). The problem is definitely instigated by altitude or ambient temp, as can easily be seen by the comments. I'd buy the sensors and install them myself but I don't have a heated or lighted garage right now. I'm a poe boy at present. I wish dealer tech's or Buell customer service would authorize to install the temps one by one and ride after each to finally end this crap or determine it isn't a sensor problem. I mean, these are new 08 bikes here. |
Stedee
| | Posted on Friday, November 16, 2007 - 08:12 pm: |
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Gary, been meaning to call, how are ya?
I just wanted to give my opinion of what I have learned. My '07 Uly has 5kmiles on it. Yes it is not smooth at light throttle openings. Actually, it can be annoying. After reading the factory service manual and talking with a few folks, I have decided we are the victims of a primitive fuel management system. I think at this time your techs are telling you the truth, that there is nothing wrong. What I don't hear is that this is as good as this system can get. The fuel control doesn't have enough inputs. It relies on load from the TPS I've been told. Most Auto systems use a MAF or MAP(older) for primary fuel control. In basic words, the system does not gather enough info (inputs) to accurately gauge conditions and precisely deliver rapid ,accurate (output) response.
I guess it's good for what it is, but falls far short of Honda or BMW systems.
Over the winter months I plan to try a Drummer. I called K-D fab and they claim this will greatly help this condition, to the point where you could ignore it. Another route I am considering if I do not get the results from that is a module from Dobeck. I spoke to them and they have a Beta unit they are developing specifically for the Uly that possibly could help.
Inaccurate fuel metering during light throttle openings are what i'm noticing with mine. This module has 4 adjustable pots that are supposed to allow some more tuning. It seems as if the engine is too lean at times. Possibly to pass emissions, not sure. That rear cylinder I suspect is on the extreme lean side at times during operation.
We have a couple inches of snow here now. Riding is limited now, at best. |
Loucksgl
| | Posted on Saturday, November 17, 2007 - 10:43 am: |
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Stedee - Bingo! And I think you are right on with your thinking. Makes perfect sense too. Everyone keeps reinforcing the new ECM and electronics on the 08 Buells that it makes one investigate and focus on the extremedies-sensors and the like. I will impatiently wait for more info from you. Wish I had a non Buell ECM to plug into just to see. But its cold out now and My Uly is running spectacular for now. Couldn't ask for a better running machine. At 60 degrees and above she's unbearable. Amazing difference.
By the way; I rode Sycojomo's bike yesterday and noticed what I'd call a very slack primary chain condition that could affect the entire range of his riding. I really didn't feel the surge in his bike like mine has in hot weather. I hope the adjustment cures his woes.
(Message edited by loucksgl on November 17, 2007) |
Iamike
| | Posted on Saturday, November 17, 2007 - 03:52 pm: |
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Mt '99 didn't run well under 2,800rpm, it felt like it was lean. After I finally got the TPS zeroed it runs much better. Are you guys sure that it has been done right on your bikes? |
Stedee
| | Posted on Monday, November 19, 2007 - 08:03 am: |
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Iamike, I think the previous owner may have had it done at the 5K service. Not sure it was done or done right. Does the dealer do this as a warranty claim if you take it to them and tell them about the driveability concern? It would make sense that they could claim enough time from Buell to cover the time involved.
I am new to this Buell thing and do not understand why you need software or a scan tool to adjust a TPS. I would think you could do it with a DVOM by looking at the voltage input signal to the ECM. There is apparently a minimum throttle plate opening that has to be set first and I'm thinking that is done by scan tool and the readout given is in degrees. The service manual explains what is in the system but gives little info on theory of operation.
I'm trying to put this together with the understanding I have of automotive (mainly Ford) engine management systems. Also, have not found a thread that explains what is done both mechanically and electrically.
I suppose it could be off and causing some or all of the problem. I'm hoping to learn more from others who would care to share their expertise on TPS reset.
Stedee |
Iamike
| | Posted on Monday, November 19, 2007 - 07:06 pm: |
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It is such a simple procedure that as a service person myself I would just do it if there was any hint of that sort of problem. You can score a lot of points with a customer if you fix something like that and not charge an arm & leg like some shops do.
I had three diferent shops tell me that I didn't need to do it even after I told them I had swapped ECMs. Not good when the customer knows more than the service shop. |
Heyfred
| | Posted on Thursday, November 22, 2007 - 11:04 pm: |
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TPS voltage to low. You have to manually slot the TPS and set. I had nothing but issues trying to correct my surging as per Buell and the dealer was no help. My bike runs like a champ.
http://www.badweatherbikers.com/buell/messages/384 2/297661.html?1190251518 |
Rob04xb12
| | Posted on Monday, November 26, 2007 - 09:49 pm: |
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Heyfred:
Could you elaborate on the slotting of the TPS?
My 04 is really getting bad. It pops through the intake along with the surge. Its horrible. I have the ECMspy software, and I toyed with the fuel maps a little, but with no success. Im going to try replacing those three sensors first (o2, head temp, IAT)
The TPS slot is very interesting though |
Jmp01915
| | Posted on Tuesday, November 27, 2007 - 01:23 am: |
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hey
I finished my ecm spy cable this weekend and took my laptop into the garage to try it out on my 99 S3 with a race ECM. I took off the air cleaner, wrote down the idle throttle setting from ECM spy, backed out the idle adjust cable, wriggled the throttle back and forth, discovered that there was some binding in my throttle cables, fixed that, got a good zero reading on the throttle, and told ECM Spy to do the reset. Then I put everything back together, dialed the idle adjuster until i got back to the same idle adjustment reading in ECM SPY.
The result was pretty good!. my 2k rpm to 3k rpm region (mapped) was very uneven before, and it is now reasonably driveable. I recommend a tps reset to anyone who is having problems with rough running below 3k rpms |
Sparky
| | Posted on Tuesday, November 27, 2007 - 01:32 am: |
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Rob04xb12, before replacing sensors blindly, you might check the simple mechanical stuff first. There is a plug on the vacuum port below the throttle body. Check if it is still there and not cracked. Also, you might test for intake manifold seal leaks while you're in there.
Either of these would amount to an intake leak, causing rough running and poor driveability. |
Heyfred
| | Posted on Tuesday, November 27, 2007 - 03:31 am: |
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The TPS has 2 bolts holding it onto the throttlebody, I believe it requires a 7mm to remove it. Using a round file, slot the top hole in the sensor on the left side so you can rotate the sensor to the right.(This is as if you are setting on the bike)Do the same to the bottom hole, but slot the the left side. TPS voltage on the unmodified TPS on my bike was .633v at closed throttle. From my experience from working on late model Mustangs, baseline TPS voltage was to be set .980v at closed throttle. I figured I would try this. First set idle, turn off bike, turn key on and do not start, at closed throttle position, rotate TPS by loosening the the 2 bolts holding the TPS. Rotate TPS till voltmeter reads .980v (close to) and tighten down TPS. with voltmeter still hooked to the TPS, open the throttle to make sure you do do not exceed 5v. |
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