Has anyone cured bucking with an open loop tune?
12-09-2005, 08:09 AM
#1
Has anyone cured bucking with an open loop tune? After trying everything I could think of to try and rid myself of bucking in the closed loop environment, I decided to try an open loop tune to let me tweak my air:fuel a little further to see if I could help aleviate the bucking. I do not have a wideband, but ive tried a half dozen different VE tables, as well as HPTuners built in realtime AFR adjustment. I tried eveything from 12.5 - 16.5 AFR with no real elimination of the low rpm low load bucking. If youve sucessfully beat this, how did you do it?
Incidentally, I keep going through o2 sensors like crazy so I may have to go open loop anyway...
Incidentally, I keep going through o2 sensors like crazy so I may have to go open loop anyway...
12-10-2005, 02:06 AM
#2
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Screw O2 sensors. Get a wideband and go open loop. If you really want to keep them, your bucking can be made a lot milder. Take some timing out of the low RPMs where it's bucking. Take some decay out it so it rev's down slower. You'll have to play with this a little though, because it will create a cruise control effect it's too low.
12-10-2005, 06:18 AM
#3
TECH Fanatic
There was a recent comment from someone else with O2 sensor and AFR issues. Basically the consensis was to look for an air leak, maybe headers etc.
The O2 will read lean due to leak, fuel will go in when its actually not required dousing the o2 in unburnt fuel, which kills them.
You might want to check in that department. Of course open loop might bypass this. If your ve is accurate you can go into open loop without much issue. If its off you will be in no mans land.
The O2 will read lean due to leak, fuel will go in when its actually not required dousing the o2 in unburnt fuel, which kills them.
You might want to check in that department. Of course open loop might bypass this. If your ve is accurate you can go into open loop without much issue. If its off you will be in no mans land.
12-10-2005, 07:29 AM
#4
Originally Posted by Nate_Taufer
Screw O2 sensors. Get a wideband and go open loop. If you really want to keep them, your bucking can be made a lot milder. Take some timing out of the low RPMs where it's bucking. Take some decay out it so it rev's down slower. You'll have to play with this a little though, because it will create a cruise control effect it's too low.
Everything else on bucking says to add timing to those areas. In any case, ive done both, and dosnt necessarily seem to help.
12-10-2005, 07:51 AM
#5
I disagree with adding timing, but if timing hasn't helped you there's no point in having that discussion. I would ditch the O2's and go with a wideband. I've been running without O2's ever since my HPtuners showed up over a year ago with no issues. I even took it cross country and back without any issues. No bucking, no surging, no problems. Just my .02.
BTW - the post that Nate made earlier was me on his login. If you want to try to keep running O2's, send me some histograms while it's bucking and your current tune, and I'll see if I can get it to quit bucking for ya if ya want. I'm mainly interested in advance and your ltrms there.
BTW - the post that Nate made earlier was me on his login. If you want to try to keep running O2's, send me some histograms while it's bucking and your current tune, and I'll see if I can get it to quit bucking for ya if ya want. I'm mainly interested in advance and your ltrms there.
12-10-2005, 07:52 AM
#6
