I have noticed my fueling is more consistent in open loop and i really like how stable the wideband readings are. How many people run in open loop full time and can someone tell me some downsides? maybe some things i may be overlooking.
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I have noticed my fueling is more consistent in open loop and i really like how stable the wideband readings are. How many people run in open loop full time and can someone tell me some downsides? maybe some things i may be overlooking.
been running full time open loop for years, honestly.
Open loop doesn't have the lean/rich switching of the narrowband sensors, that is why the numbers stay pretty much the same all the time. A downside is that you need to be on top of it more when the climate changes. Big swings in ambient temps or humidity can change things.
I've always tuned in open loop and switched back to closed loop when I was done. Having the wideband swing from 14.0-15.2ish never bothered me at all when I went back to closed loop, that is just how it is. Certain applications make closed loop not ideal, like turbo vehicles where the exhaust doesn't really make it easy.
Does anyone know how much a bigger cam with more overlap effects the stock narrowband's feedback accuracy. I notice the same thing you are talking about with it swinging way too much in closed loop. I realized I was wasting time trying to tune VVE and MAF with a wideband as it would seem like the histogram was rich, then you run it some more and let it idle back to the same cells then it averages back lean. I pulled the wideband out and starting using LTFTs and it seemed like everything was a lot more consistent with less transient feedback messing it up. Now I am thinking again since it seems idle cells will be lean then you go run the car for a while then go back to idle and then it averages back to rich, so now I am at a complete loss and completely confused. It appears maybe the cam overlap with the extra EGR effect or something is messing with the narrowband and maybe both the wideband feedback as well?
i run with the wideband installed all the time now so i will monitor how thinks change as summer approaches. your right there is no control error to the wideband if my tuning is correct. that i do like. i need to spend more time with o2 settings so if i do go back to closed loop the fuel trims dont try to unlearn what i have done. that is my biggest concern. cmitchell17 the "perfect" scenario for me would be to get the stock narrowbands tuned to match my wideband readings within human reason and then go from there with the maf and vve. i have not been good enough to get that correct yet(which is why i am considering full time open loop) but i will at some point.
I've been fighting this for a while being that I have the perfect application for o2 sensor tuning. Stock air box with BMS filter and 2" long tubes. I've tried just about every setting you can think of and at the end of the day, stock settings work best.
when i am done the vve i will turn the trims back on and try stock settings. thanks