| Author | Message | ||
     Eweaver |
My 2009 1125R California model is having a bit of trouble. After resetting the AFVs, the front always creeps back down to the low 80s. Which makes the bike run like crap. I installed a K&N to see if that would help. Dealership installed new intake gaskets, but nothing seems to stop it from creeping down. I ran a Torquehammer for a brief amount of time, and the AFVs stayed at 100. Has anyone suffered from this and found the source of the problem? | ||
| Gemini |
not an exhaust leak, sounds like a bad o2 sensor or wiring problem to the o2 or bad ecm. | ||
| Hd8803rider |
Nope, it's not that it is how they have the fuel return line off the Cali canister as I live here in Nebr and had it the stock 49 state way and my AFV was much higher before adding the Cali Canister on my bike, as I bet it's adding fuel to it making it lean if I over fill or if the fuel over heats | ||
| Xoptimizedrsx |
I'm with Gemini. Check that 02... You may have a bad setting in the ecm telling it to run at a very lean condition. Can the wires get switched. I dunno I have not looked to see if that's possible... If you can read the afr when its at the low condition on a wideband that would tell you lots of things.. | ||
| Gemini |
STOP....is it both front and rear that go to 81%? no likely that two o2s are bad at the same time. maybe rider is onto something there. | ||
| Eweaver |
Thanks for the input. It is the front only that goes to 81, the rear has never budged from 100. | ||
| Eweaver |
I also suspected the Cali can feeding into the front throttle body. I am pretty sure that is not the case. I plugged the hose, then the AFV made its final plunge from 85.5 to 81. | ||
| Gemini |
then i would be back into looking and an input problem from the 02 sensor. engine off, go into diag mode and see what voltage the front and rear o2 sensor is at during the engine off/rest state and go from there | ||
| Hd8803rider |
Unless you did a reset of the AFV after you plugged the hose, it was still taking a avg of all the data still in the system I would bet, as my front AFV is now 97.5 Rear 104.5 as the front was 88 after I overfilled the tank once after getting the Cali Canister on it and it ran bad for a short, till I figured out what I did, but now the Avg AFV is inproving it's Data, giving me a better reading on the front Cyl | ||
| S21125r |
It would say you are getting a rich condition somewhere that the ecm is trying to make up for. I don't have the cali can so won't speculate too much, but sounds plausible to me. Possible also that you have a bad injector pintle and it's allowing fuel in during injector off time. | ||
| Eweaver |
front and rear O2 voltages are .4 | ||
| Gemini |
assuming they are the same part number(i am not sure one way or another), try swapping the front and rear sensor. | ||
| Eweaver |
Gemini, thanks for the help. I don't have any time right now for experiments. I am mechanically capable, but time challenged. I am hoping to find someone that has already figured this out on their own ride. | ||
| Highscore |
I have struggled with the same problem on my 1125R: After a reset by the dealer to 100% AFV, the mixture drifted away after a short period of driving. The following screen shots show the effective injector timing, the pulse width, for front and rear cylinder at WOT during an acceleration from 3000 upward to the rev limiter. The graph shows the fueling for a refreshed 100% AFV:  Front an rear are jetted different. Especially in the first part of the data log, at the very beginning of the rev range. there is a huge difference in injector timing and fuel supply for each cylinder. The reason for this is evident: Its the difference in header length for front and rear cylinder. The front is fairly short, boosting engine performance at the beginning of the range and at the top, the rear one is rather long, laying the cylinder performance peak in the middle of the range. After a short period of riding, the engine fueling changes like this:  At least after 100 miles the front cylinder starts to run dramatically lean compared to its partner at the rear. What is the cause for this phenomenon? It is the aftermarket exhaust, I have installed. I prefer the new quiet street legal and EC-homologated Remus-system. This pipe offers substantial power and "works" even below 4000, the margin, the pure and simple stock primaries even start to work.. When adding additional header length to the stock headers, you may aspect such an effect:. Additional grunt at the bottom of the range. The only thing, which makes the Remus different, is its "social acceptance" regarding noise. Otherwise it works like the other "race cans" around, connected an additional common down pipe to the two primaries. The "closed loop" area, where the ECM calibrates itself and defines its AF-value, is just a small window up to 4500 rpm during light load, approx. 1/8 throttle opening. Unfortunately the healthy aftermarket pipe effect, which boosts low end grunt so nicely, on the other hand effects also the engine breathing under said light engine load. The "closed loop" adjustment by the ECM tries now its best to restore the fuel to "stock settings". But this setting are correlated to the stock pipe, not the modified, prolonged aftermarket lay out with an new additional down pipe. This "corrected" AFV-ECM settings simply do not suit to the aftermarket exhaust. So it runs worse with this "adapted" fuel settings. Its runs like crap and with a real bad fuel economy. Sadly enough - in my sense a false approach of the Buell ECM-adjustment, the same settings, detected to be "correct" for idle and "closed loop" are also valid for WOT too. This is curious, because this assumes that internal engine (and wave-)action is the same for light loads and WÖT. This is definetely not true. After I saw this "fuel drift off" twice, my personal solution for my private 1125 was to disable closed loop by unplugging both lambda probes. Instead of the probe I have soldered a 1 Meg-Ohm resistor , which is attached to ground, onto its ECM signal wire. This works without any failure code and keeps the AFV strictly at 100%. This ECM-tune is now the basis for my own fuel modification. Now I have really nice driveability without any drive line issues and a fuel consumption of incredible 40 mpg instead o 30 all stock. Furthermore the engine now runs definitely cooler without heating the frame such tremendously as it has done stock. (Message edited by Highscore on May 31, 2010) | ||
| Cataract2 |
Hm, mine have started to do the opposite. I just got my Drummer back after having some work done to it. Had the tip moved a bit and got the DB killer installed from Kevin. Now my front AFV is 109.5 and my rear AFV is 89.5. Before the rear would site around 100 and from would be 105. Odd. I'm thinking about getting the Erik Buell Racing Race ECM for this now. | ||
| Eweaver |
Highscore, WOW! Thanks for the complete report! It will take me a moment to wrap my head around everything. So, you are blaming this on a correction due to the aftermarket pipe? I have this issue with the stock pipe. Thanks again. I really appreciate the time you put into this post. |
