| Author | Message | ||
     Speedfreaks101 |
I searched the forums are read about other people having the 4000 rpm stumble issue with the TFI unit. I have still yet to find any post a "cure". More than anything I have been searching for common ground between the people having the issue but I can find none. I will be trying different combos to tune this problem out this weekend so if anyone has any input please post up. | ||
| Typeone |
what are your pot settings? especially interested in the 4th pot. sometimes you can cure the stumble at 4K by increasing the 4th pot to 8 or 8:30 the highest. i would test from 7:45 up making sure you let the system learn in between each run. still curious where you're at now with each pot though. here's one of the many posts you'll dig up 'round here... http://www.badweatherbikers.com/buell/messages/32777/104819.html | ||
| Rr_eater |
Spead, Mine was cured after dyno tuning. Honestly it is the only way to "get it right" really. Others will argue, but 150 bucks worth of tuning saved a TON of headaches!! Just do it, or get the Data-link sytem. Bruce (Message edited by rr_eater on March 25, 2006) | ||
| Typeone |
Rr_eater, how did you're dyno session go? i paid $100 last year only to have the tech twist and turn dials all over the place say, 'yup, thats getting good', with no learning in between. felt good for a few miles then the bike ran like crap after the session. i just logged the settings with all the other settings i was testing but the pots were waaaay off from where i am now. just curious how your dyno tech achieved success. planning to dyno tune again this year. | ||
| Rr_eater |
Dyno session lasted almost 2 hours total. Tuning on a dynojet 250 allows you let let the bike relearn between changes, then do your power pulls, so we were able to simulate road riding, without all the traffic!! I do remember that the 4th POT was a bit higher then normal settings, as were all the POTs except 1. Chris also reset the AFV between every POT tuned, and 3 minutes steady state between pulls and runs, why it took almost 2 hours. I had it close based on recommended settings, had the surge, had it tuned, no surge and great power curve, which IS posted in another thread, somewhere.... Patience seems the key, and a guy operating the bike/dyno who really gives a crap. Maybe some of you have heard of him?? Chris Rivas, Buell prostreet drag racer?? He was the only guy at the Fresno HD dealership who would actually try, because he digs Buells. I think attitude towards a marquee has a lot to do with it. If they dont care, it will be crap. My .02 and info Bruce | ||
| Typeone |
Appreciate the info, Bruce. thnx! | ||
| Speedfreaks101 |
Well as far as my settings here is what I started with 4 9.5 6.75 7 and now I am using (still testing) 4:30 6 7 8:45 I changed settings all day long and found what I believe to (possibly) be useful info. I only rode about 20 minutes on the last adjustment so I am not sure how it is doing just yet but I think that the second pot needs to come up some in order to improve rapid WOT situations. Now the following is what I think is going on and I may be wrong but I will be talking with George from Dobecks tomorrow and I will find out if I am right. It seems like the second and third pot settings combined determine where the fourth pot should be set. Almost like there is a ratio that you are shooting for. Now when I get rid of the surge in the 4000-5000 range then the adjustment that I have made brings in a hesitation in the 2800-3500 range ,hence the before mentioned association between the cumulative settings. I do understand that the dyno is the answer but to honest I am having a hard time finding someone local. If I could find someone local that understood how to tune a Buell and had a dyno with the ability to load the then I would gladly purchase the software and the key from American Sport Bike (you also get a 24 page manual from that Al has written that further explains the ECM's manipulation when you buy from American Sport Bike)software. I have actually found some plans to build a dyno and have been speaking with some a good friend about helping me set one up. That may be my best solution. Later, Bart |
