| Author | Message | ||
     Midmofirebolt |
Alright, I've got a 12R and had the race kit on it(filter, ECM, exhaust), bought a D&D and while I was installing it, decided that I would pull the snorkel on the airbox. After that I ended up with a lull in acceleration around 4k rpm. I put the snorkel back on and still had the lull, just not as noticeable. I'm thinking the snorkel makes it less obvious because its reducing the output and therefor the difference. But no matter what, I still have the lull and I can't stand it. Has anyone else had this problem? Ideas? | ||
| Daves |
Just so I'm clear on this, you are talking about the snorkel that goes thru the frame and not the velocity stack in the airbox, right? The reason I ask is when the race kit was installed the snorkel should have been removed. Did you ride the bike at 3500 RPM or so for about 10 miles for the ECM to "learn" the new pipe? | ||
| Midmofirebolt |
Yeah, the rubber tube that goes from the airbox to the intake scoop. it was still there. And I tried to let it learn the new pipe, tried to keep it in the 3k's for a while. I guess I'll try harder. Around 3500 rpm for 10 or so miles. I'll get back to you tomorrow and let you know if that helps. Thanks. | ||
| Dcentric |
Did you have the adaptive fuel value reset? It may be running at an 80% value and need to be reset. | ||
| Jerseyguy |
Dcentric - What is the adaptive fuel value and how is it reset? I couldn't find it in the shop manual. | ||
| Captjim |
Jersey, From what I understand the AFV is a continuously changing parameter that controls how much fuel is used by the ECM. It is designed to give the computer some variability to compensate for atmospheric conditions and differences between the stock motors. If you cut the airbox and put a high flow filter on an otherwise stock bike the AFV may creep up to the top of its range. Could be useful to monitor the state of the AFV. You can reset this value with the Technoresearch software and with the factory digital technician software. It seems to be a rule of thumb that when an engine mod is done, such as exhaust or filter, the AFV is reset to facilitate the ECM in learning the new engine configuration. I think it would learn over time anyways. Hence, everyone saying ride your bike for 15 minutes at 3500 rpm. | ||
| Jerseyguy |
Capt' - I see. This is the parameter that is learned over time by the ECM. The thought did occur to me in the past that I'd like to reset this value to its default for a "clean" relearn. I put a Chrysler performance EFI in a carbureted Wrangler some years ago and every time you disconnected the battery, the EFI would have to relearn its parameters. You could really tell because for the first minute or 2 it would idle rough & stumble. I guess disconnecting the Buell battery doesn't reset this parameter to the default. | ||
| Buellman39 |
No Jerseyguy disconnecting the battery does not reset the AFV it saves it just like the TPS setting.  | ||
| Dcentric |
Cappie's right, If you go on a 20 minute ride and maintain at least a 3500 rpm it "should" reset. I think for my money in the bike however, that it's good to let a shop do it so you can be sure that you are fully utilizing the bikes performance. | ||
| Jerseyguy |
The MPG computer on my Jeep Overland would calculate the average MPG since the day it was started if I didn't reset it now & then. I'm wondering if the AFV is a similar situation. That would mean that all data from previous setups would be averaged in to the current value. Maybe in time that old data's effect would be trivial to the overall average. It would be nice to reset it to a baseline though.... | ||
| Bigeasy |
Thanks guys. Just put on a D&D a week ago and she seemed to lose power. Loved the sound though. But now it seems the more I ride it the stronger it gets! This thread seems to have explained alot. | ||
| Yeags30 |
Mine stumbles right before 4000 rpms as well. Once the bike is warm it seems to go away. Mine has had issues starting lately as well. I need to get a 3k service done anyway so i may bring her to the dealer | ||
| Fullpower |
what is a 3K service? | ||
| Opto |
Maybe in time that old data's effect would be trivial to the overall average. It would be nice to reset it to a baseline though From my experience the AFV doesn't work like that, it adjusts only if you cruise for a while and it stays there until new data comes in saying lean out or richen up a bit. So it's more or less set/influenced from the last ride. I'm running another FI system in parallel with the stock ecm and the stock ecm has leaned out to the point of barely able to hold a cold idle (because I'm running rich on the other FI system). One good ride down the highway and all is back to normal with the stock ecm. I think the AFV changes readily for day to day conditions. I still don't know if the ecm needs a power cycle (turn motor off, start again) to set the new AFV or whether it does it on the run, I do remember my bike having a stumble and then coming good after a short while on the highway after fitting a new pipe, but that was only once. | ||
| Ingemar |
Like Opto said. Past changes do not influence the current AFV. It does not record an average or something. It adjusts as you ride without looking back (and I wish humans could function like that too sometimes). | ||
| Midmofirebolt |
My lull seems to be working itself out too. The only time I really notice it is hard acceleration in first, and I most of the time I can't feel it. So I guess it's learning. I'm starting to think my bike might be smarter than some of my friends. Thanks for all the info guys. | ||
| Jerseyguy |
Opto & Ingemar - Thanks for the info guys. That's one less thing to worry about. I'm wondering now if the TFI pot #4 alters the AFV's response. | ||
| Captjim |
There was a post made a while back relaying information from Doebeck about pot #4. Something like #4 providing a false signal to the ECM so it wouldn't try to adjust its own fuel values. Since the TFI is adding fuel if left unchecked the ECM would try to pull fuel out. Makes sense but can't seem to find the post. It was something like that. | ||
| Opto |
I remember that post, makes sense to me. Steve I've always wondered if the 4th pot alters the AFV, it "shouldn't" if it's set to the right spot but who knows if the AFV would start creeping one way or the other? If you disconnected the TFI and did a highway run to reset it, then reconnect the TFI and compare before and after Lambda then you might get an idea if it had shifted or not.(All this is assuming that the AFV actually exists and works like we think it does - I've read no hard evidence about it, it's all just pure speculation on my part unfortunately, an hypothesis perhaps) I hope to be fitting a TechEdge 2CO wideband O2 setup this weekend, it will be interesting to see the fuel delivery of the stock 12 ecm with old Drummer and K&N...  I'm thinking it won't be too bad, but we'll see. | ||
| Ingemar |
The ecm uses mainly the lambda readings to calculate AFV. The voltage the lambda gives out varies as there is more or less oxygen in the exhaust gasses. It is my guess that the 4th pot gives out the voltage for the lambda to the ecm that it considers 'ideal'. In other words, with that voltage the ecm will no longer try to adjust the AFV based on the lambda. But like Opto said, its all speculation. The o2 sensor is the main input for the ecm, but not the only one. So I think with a fixed o2 voltage the ecm will still adjust. I played with that 4th pot and really didn't notice a difference. Right now it runs pretty good and I haven't had any hickups lately. Current settings are 1=3, 2=3.5, 3=4.5, 4=default. Now some have mentioned that around 4000 rpm there is a transition from the 2nd to the 3rd pot. I really wonder if this transisiton is fixed at an rpm, or if it is hooked up to the tps as well. Dobeck mentioned once that their device has "load detection". They also say that the pots are similar to jets in a carb. Jets in carbs work mainly on how wide the throttle is opened, less on how fast the engine is running. When I experimented with the pot settings I once had pot 3 on 6. As soon as I would open the throttle more than half it would stall even below 4000 rpm. The smell of gas confirmed it was too rich. | ||
| Jerseyguy |
I REALLY wish Buell would come out with a fully programmable ECM. I'd love to tune around A/F and see what I get. I'm just running the Race ECM now & the bike runs fine. I have proved that it does go quite rich on moderate to full throttle openings throughout the range and lambda is a little under 1 under more or less steady state conditions. Most of what I've read on lambda is related to water cooled engines and I wonder if air cooled engines need to be rich on high throttle openings to keep cooler, hence the race ECM's response. | ||
| Opto |
It took me 2 weekends, looks like the stock 12 ecm is running the bike as lean as it can without upsetting the motor too much, AFR's of 14 to 16:1 are common at cruise, hence the good fuel economy. Haven't datalogged WOT yet (well I did but the Palm locked up) will find out soon. | ||
| Sik_s |
Just so I'm clear on this, you are talking about the snorkel that goes thru the frame and not the velocity stack in the airbox, right? The reason I ask is when the race kit was installed the snorkel should have been removed. Must have missed the memo. I just installed the same stuff, but didn't know that this had to be removed. Not exactly sure what it is, anyone got a picture or provide some guidance. |
