| Author | Message | ||
     Brotherbuell |
Picked up my bike from the dealer yesterday. I had to drain some oil because it was overfilled and I have to figure out what's causing the bike to "stumble" when I grab a hand full of throttle. It seemed to get a little better as the bike warmed up but was still there. What really ticks me off is that it was running perfectly before I brought it in. I wonder if they screwed up the TPS reset? | ||
| Alchemy |
Hi Brother Buell, Just had the 1000 svc. Mine did the same thing before and after TPS reset. It tends to "pop" through the airbox and then stumble when opening throttle aggressively from an idle. This may be different from your experience. I wonder if it has to do with the type of fuel. I have been using Sunoco Ultra thinking it would help. It is more noticeable when it is cold than when hot. | ||
| Chrisb |
Take it for a ride and make sure its hot. i.e. fan has been funning for a 5 min or so. THEN Try to get a staedy run for 10 min of speeds below 60mph and above 25 with RPMs 2500-3500. | ||
| Brotherbuell |
Alchemy, Yes..that's exactly the same problem. Chrisb, Thanks I'll give that a try. | ||
| Alchemy |
Br Buell, Does you idle seem to be set correctly? Mine seems to be lower when cold and then ends up about 1080 or so. Have you noticed that this happens more when starting from a grade vs on the flat? I wonder if a partially fouled plug could cause this? | ||
| Birdmanrh |
Ya know, a good dealer is hard to find....regardless of the brand. | ||
| Pso |
Brotherbuel-Check out my post "from best bike to worst bike" on this board. I had/have the same problem. It started at the same time, after the Hardly dealer did the 1000 service and side stand recall. I think that I have now narrowed the problem down to being the throttle position. I have found that I get that stumble when the throttle is open about 1/5 or 1/6th. On my old carburated bikes I would have just opened the idle jet a turn or so and if that didnt resolve it I would have lifted the needle a tad, but I am at a loss as to what to do. I end up driving at higher RPS just to keep the throttle open more. I do not like to run at a constant 4500 to 5000 rpm, but at that rpm it runs as smoothly as it did at 28 to 3200 rpm. I am going to go to a different Hardly dealer and see if I can get this straightened out. Also I plan on going to the Buell event on the 23rd in NJ and check with the tech folks there. I realy like the bike, I think overall it is the best bike I have owned since '59. I traded up from an 1800 Goldwing for this bike and find that this bike is as comfortable and more fun than the wing was. As a long distance rider if I can not get this glitch out of the bike, I guess I will just need to get a differnet bike that does not have this type of anamoly. The other things I do not find to be a problem for me(fan, side stand recall etc) and I think that the factory responsivness is superb, plus I like and support the entrapernurial(sp) spirit of Mr. E. buell | ||
| Alchemy |
Another question: How much slack is there in the throttle grip control before the engine responds. When new my bike had too much IMO. I had to turn around an eighth of a turn to get the engine to respond. This has been reduced by adjusting the 2 cables. I did this before the TPS reset at 1000 miles. I don't directly relate this to the stutter but it might be part of understanding things. My stutter was present before and after the TPS reset. | ||
| Red_chili |
Pso, for goodness sake don't dispose of the bike for that. Interesting description; mine is doing similar things at similar mileage, and the pilot/needle approach is how I described it elsewhere. From what I have perused, a more open intake, race ECM, and freer breathing pipe pretty much kibosh the problem. So does continuing the break-in period... things change till then. YMMV (Message edited by red_chili on September 15, 2006) | ||
| Snowscum |
I have the race kit and it still stumbles once in a while. | ||
| Alchemy |
After a discussion about the stumbling, I am going to check for an intake manifold leak. This would be consistent with something that may be dependent on temperature and come and go to a degree. | ||
| Pso |
Thanks Red_Chili-Recommendation taken. I wonder where to start. I was thinking a drummer exhuast to remove the exhaust valve thing. My logic being that is where the hang up might be -some sort of switching mechanism. | ||
| Brotherbuell |
Alchemy, The idle setting seems fine. There is no difference on a flat road or grade.The plugs were supposedly cleaned and gapped as part of the service. The throttle play is about as it was when I took delivery. I am going to check the exhaust valve operation since the muffler was removed to replace the kickstand. | ||
| Pso |
Brotherbuel-After my first 1K service I took the bike back for a reset of the TPS. the throttle play stayed the same. I am also going to check the exhaust valve operation at the muffler also. I checked on the top of the air cleaner and the cam works fine but I also had the muffler removed at the same time as the service for the side stand recall. I hope they pinchecd the cable or something. Let me know what you find | ||
| Red_chili |
Pso, Friday night was the first time I've been able to run the bike for 20 mins at 3500 RPM to reset the ECM since the 1K service/TPS reset. It definitely made a difference, worth a try. Should be the first thing to do when facing a lean stumble off idle. Also, the idle is slightly low and I aim to fix that today. When Buell makes an ECM that does a more dynamic adjustment to real conditions (not requiring the 20 min thing) it will be nice. That said, my Toyotas require something similar (not RPM, just miles) before optimizing. (Message edited by Red_Chili on September 17, 2006) | ||
| Alchemy |
Red_Chili, This resetting the ECM by running for 20 minutes is new info for me. Is this the stock ECM you are referring to? Is there a good thread on this so explain all this? | ||
| Davo |
AFV resets after the engine is warmed up and you ride for 2-4 minutes with steady throttle (very little change in TPS) on mostly level conditions. No accel or decel. I ride at 55 steady for about 4 minutes to be sure. That value is stored for open loop operation. Closed loop is doing real time changes constantly by reading the O2 sensor and making AFR adjustments. During these closed loop changes the system reviews the data and uses a formula to determine what would be a efficient fixed and stored AFV to use when the engine leaves closed loop for high load or non cruising conditions. | ||
| Red_chili |
Great info, Davo. Everything I've read here to date has used 15-20 minutes minimum at 3.5-4K, first I've heard it only takes 2-4 minutes. Not that I am not pleased to hear it!! I'm assuming you've gotten this info by observing the actual values changing in your other research? Good news. | ||
| Davo |
Red chili, I got a tip from Australia. Yes I have done a half dozen AFV resets in the past several days. I then verified the new AFV in less than a 10 minute ride! The key is to keep the TPS very still while you cruise at 55 mpg. I road about 3-4 minutes, did a couple small wheelies during the turn around and then steady back to the shop. I have been manipulating the AFV and freezing it in the ECM for fixed open loop operation. I am now working on a closed loop manipulation but I have run into some connection issues. It may take a while to figure it out and it may not be possible at all w/o keys to the kingdom. | ||
| Red_chili |
It sounds like to some degree you are wanting to alter the ECM's logic from the exterior? Interesting. Had a good PM response from Al Lighton, very VERY enlightening. His take on what feels like a lean surge is that the ECM is 'hunting' stoich in closed loop by a larger swing than we might wish, missing a beat here and there as it goes lean and corrects (my choice of words, not his). It is a partial throttle situation ONLY. It then uses its calculated AFV for open loop too. (You probably already know all of this, I am just thinking out loud.) So in essence, would it be fair to say you are trying to convince the ECM to go a tad richer than stoich to compensate? So it comes up with an AFV that is slightly rich and there is no lean miss in the stoich hunt cycling? That would be my gut instinct from dealing with a hot-blooded XR650R and taming partial throttle leanness+heat with a richer pilot and hotter thermostat. It worked with the XR, perhaps at a slight loss of efficiency, but frankly my dear.... boiling coolant is not the kind of efficiency I want in the woods. However, it ain't exactly the problem with the Buell ECM if I understand Al rightly. Again, however, if it masks the problem such that I cannot tell its there, and there is no particular downside... do I care? Seems like you really need to make the ECM slightly mis-read the O2 sensor then. Like a TFI or something. Otherwise I don't know how you are going to convince the ECM to hold to a condition it is programmed to avoid. It needs rose-colored glasses.  Am I following correctly? The real problem does seem to be we are dealing with an ECM whose equivalent in the automotive world last saw the light of day before OBDII. Like, 1995. (Message edited by red_chili on September 19, 2006) (Message edited by red_chili on September 19, 2006) | ||
| Red_chili |
Disclaimer for the non-Buell public: the lean surges (not necessarily what is really happening) I would rather do without are very, very slight. It is just a tad annoying, bucking very slightly under part throttle conditions and running slightly hotter than it really needs to IMHO. Not many scoots DON'T do that these days. | ||
| Brotherbuell |
Cured!!! As suggested, I ran it at a steady 3K for 10 minutes and viola...the off idle stumble is gone. Thanks everyone for the help. Man it's hard to drive this bike that slow for that long. I still think a first class dealership would have told the customer to expect this and how to fix it. | ||
| Pso |
Brotherbuell: I did the same and got the same results for a major surging. I still have the slight partial surger that Red Chile is talking about. Only at very slight partial throttle. | ||
| Davo |
Pso, Surging at what RPM? |
