BLMs say rich, but WBO2 and NBO2 and surging all say lean - what gives?

[SkinnyG]

Odd. I thought I attached one. Now attached.

The $4D is a pretty spartan computer by comparison.

[delcowizzid]

980mv full throttle she's rich .the old ecus also lock timing at lower rpm while in aldl mode it could be real retarded .where are your narrowband and wideband sensors installed if you install them one behind the other inline too close together you will get weird readings

[SkinnyG]

You -should- be rich at full throttle; the Wide Band says 12.6 AFR at full throttle, which is what you want. Even at idle and cruise the WB is around 14.7, but the ECU keeps pulling fuel. I set the BLM limit to 120, becase it would go 108 and run super lean.

It -is- getting timing, I've checked.

I am using an LC-1 sending WB to a gauge and its emulated NB to the ECU. This ECU won't let me feed a WB for datalogging. While I have read that folks have had issues with the emulated NB on the LC-1, this ECU was doing the same thing with the original NBO2 the engine came with, as well as a brand new one I bought. O2 is mounted at the collector.

I do appreciate the input and help. :) I can't figure this one out.

[dktool]

Even at idle and cruise the WB is around 14.7, but the ECU keeps pulling fuel. I set the BLM limit to 120, becase it would go 108 and run super lean.

This sounds similar to the way my 7060 / $D8 system operates, the original minimum BLM value is 84 and it will pull fuel sometimes all the way down close to the minimum and all the while the WB02 holds steady at 14.7
It seems to be under 50 map that it occurs the most, I played with lowering the V.E. in the rpm / map ranges that are most obvious and it lessened it some, when I changed it enough to keep the min BLM around 110 it would show a very lean condition on the WB02
When the P.E. comes in the WB hits exactly 12.0

It was something that was more curious than anything else as my overall tune is running fantastic.
I have watched the live data for hours at a time while doing long road trips, everything else looks great.

With all the emphasis on BLM numbers in the hundreds of posts I have read I tried real hard to get that magic number range everyone talks about but have come to the conclusion that this 7060 may well be the black sheep that eaglemark once eluded to.
I just ignore the BLM data and use the WB as my guide.

[steveo]

there's also the argument that if you're going to run closed loop, you are never going to achieve the wideband AFR, all you'd be doing is making the BLM system work harder and harder to achieve an erroneous goal, so tuning to the trims would make more sense.. even if the AFR isn't great, at least it's consistent.

in other words i would tune to minimize trimming or abandon closed loop and tune OL with your wideband.

as far as PE goes, either method would yeild a reasonably accurate base fueling shape upon which power enrichment can be tuned properly to the wideband target anyway

[SkinnyG]

...so tuning to the trims would make more sense.. even if the AFR isn't great, at least it's consistent.

in other words i would tune to minimize trimming or abandon closed loop and tune OL with your wideband.

Am I understanding you correctly in that I tune so the computer/BLM is happy with whatever the end result it?

Could I just change the listed "stoich" to, say, 14:1, and the computer will stop trying to pull as much fuel out?

Or could I change the O2 Voltage Thresholds to higher switching points?

Just trying to wrap my head around all this.

Thank you all so much for your help!

[myburb]

I am not trying to be a smart ass but I don’t understand. Above there was a line in the post.

Even at idle and cruise the WB is around 14.7, but the ECU keeps pulling fuel. I set the BLM limit to 120, becase it would go 108 and run super lean.

Which is it, 14.7 or lean? It can’t be both. If the WB stays at 14.7 the ecm is doing what it has been ask no matter the blm say. It would only look like the ve table wasn’t very good.

[steveo]

Am I understanding you correctly in that I tune so the computer/BLM is happy with whatever the end result it?

Could I just change the listed "stoich" to, say, 14:1, and the computer will stop trying to pull as much fuel out?

Or could I change the O2 Voltage Thresholds to higher switching points?

Just trying to wrap my head around all this.

Thank you all so much for your help!

nope, closed loop is only capable of targeting what it percieves to be stoich, thats just how a narrow band trim system works. altering o2 voltage targets might get you +/- 0.1 afr or something

[dktool]

I just ignore the BLM data and use the WB as my guide.

I misspoke here, I meant " use the WB as a reference" being just to monitor what the CL fueling is doing and under all conditions (except P.E.) it runs at 14.7 regardless of what the BLM number is.
Is that odd ?

It's when I tune the V.E. to achieve a higher BLM number that it swings so lean that the drive-ability is gone.