Create maps of HO2S11 and HO2S21 with LTFT's and MAF on the axes...Originally Posted by ddnspider
to do this follow the map tutorial, just change the pids used on the Data, Row, Col tabs...
let me know if you get stuck.
Create maps of HO2S11 and HO2S21 with LTFT's and MAF on the axes...
to do this follow the map tutorial, just change the pids used on the Data, Row, Col tabs...
let me know if you get stuck.
Thanks Joe. I should be good with creating the MAP as I've done that before. I was getting stuck with this in particular because you're really referencing 2 different tables with 1 MAP. 1 is closed loop mode vs O2 mV and the other is g/sec MAF vs. Closed Loop Mode.
I must be missing something... Why are you wanting to mess with the o2 switch points at all? To tune the Maf it would be maffreq on the y-axis and populate the table with the Ben from your wideband. Oh wait I think it just clicked, are you trying to tune this car with your nb02 ?
03 Silverado 5.3 ECSB 4x4 Z71
Comp Cam 206/212 .515/.522 112 lSA, hardened rods with LS9 springs
2010 Tahoe VVT AFM 5.3
Stock for now
Sorry, perhaps I dug too deep too quickly and didnt lay enough foundation for my thought process. My gears initially started turning when I did long tube headers on my 98 z28 A4. I performed AutoVE and AutoMAF several times with a WB02 with good results. But when the system went back into closed loop, my O2's were adding LTFT's at idle that disagreed with my WB02. I did searching and found that this has happened to many people, usually because of moving the O2's placement from factory.
There was 1 particular thread on here that I cannot seem to find, where someone in a corvette was having the same issues. They did AutoVE and MAF and had his fueling within a couple percent, but when he went back closed loop, his narrowband O2's were adding LTFT's that disagreed with his WB02 and he found he had to sample and tweak his O2 switch points. This is basically where my thought process went and I figured I needed to do the same.
That reminds me of this: B4105-how-do-i-link-this-table
Hmmmm, I will have to give that a look as I was not familiar with linking. Thanks for the link!
OK, so to clarify, I'm gonna assume you WB at Idle is about 14.7 AFR ish and you are happy with this and your MAF/VE tune using the WB is good
However, back in closed loop you find LTFT wanting to add 5% more fuel at Idle compared to the WB, ie making the WB read lower than 14.7 AFR. So switching at 365 or 415 mv in CL mode 8 or 16 (IIRC) is still too high. If you set to 450 mv across the board it will add even more fuel in the LTFT (test this!).
With my headers, before cam I think I had my O2 switch at about 320 mv or something at idle airflows. I will check this weekend when I'm home.
The problem is that at idle the O2 do not switch fast like they do when driving, either that or mine are on there way out and being really slow. (they are fine at > 2000 rpms). This means that the fueling will swing up and down. To note, I cannot run CL with my heads/cam at low RPM as it causes hunting as the fueling is jumping up and down so much. In open loop where I specify the fueling, it is fine. Just food for thought. I run OLSD all the time with a innovate MTX WB in all the time to keep an eye on fuel which is band solid at 14.6-14.7 in general driving.
Yep, that about sums up what was going on. I could also tell that my O2's were switching slow at idle and they're basically brand new. This is why I've been hesitant to just set them to 450mV across the board. I'd prefer to stay closed loop to account for temp changes throughout the year. It's a 98 so I don't have some of the tables that later years do like IAT vs fuel adder.
W....H...A....T??
PS...I'm also wondering if my "low" idle is also exacerbating this since the car idles at ~550rpm's, i.e. one of the causes of slow switcing at idle.
The car lower idle will make switching slower and this is exacerbated by the headers being longer and larger in diameter too.
I run with the WB to check all the time, beauty of the MTX. However I do not see too much variation with weather but the UK is cold or cold and wet !!! I do a new retune for fueling every couple of months anyways.
Setting switch points to 450 across the board will be fine but will make it more rich at idle than now so you will have to prob set it at about 320 mv. You'll just have to fiddle a bit till you are happy
My NB are constantly dead at Idle as my AFR is about 14.8-14.9 with heads and cam, WB running lean with a mid overlap is about right, so it's tuned by feel here, if you get what I mean. My NB do an ok job but again causes some hunting cause of cam and my switch points are about 300-330 mv.
You'll just have to test it at idle till youre happy. Long as the +5% isn't added when driving then your fueling will be bang on anyway, well to stochiometic.
At WOT you will run soley off MAF or VE (if mafless) so that needs to be dialed in with the WB very well and No more fuel will be added as long as all other fuel trims are not +ve.
A cheating way to ensure WOT / PE mode is always as the WB is to richen fueling by 1% everywhere except the PE region. Thus in CL the LTFT will be -ve by a percent or two and hence at WOT only commanded fueling will be used as PE mode is not made leaner by -ve fuel trims.
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