Serial logging and tuning with 2 LC-1's

[truethinker]

hey Joe, I seem to have everything dialed in pretty close. I re-enabled my MAF and set my PE setting back to normal and activated Lean Cruise and everything seemed to work pretty well. my LTFT's settled in to +/- 0.08% mostly staying at 00. I've noticed though that my WBO2 reading is always off from one side to the other. In terms of Lambda, bank 1 is always 0.010-0.020 more rich than bank two. No matter the condition. Even when lean cruise is active and there is no O2 adjustment being made. Any suggestions on why this may be?

Also, SELBENS and VET won't look right with the MAF re-enabled and other VET setting returned to normal, correct?

Thanks


Log_leancruise_0001.efi

03SD_leancruise_0007.tun

[joecar]

Since lean cruise is commanding an AFR away from stoich, then then Close Loop trimming cannot be done (since it trims to stoich).

[joecar]

...

Also, SELBENS and VET won't look right with the MAF re-enabled and other VET setting returned to normal, correct?

Sorry, please explain the context...

( MAF is corrected with MAF enabled )

[truethinker]

Hmm I thought the trims were active up until lean cruise kicked in.

Aren't we essentially deactivating Maf based correction by changing the threshold for Maf calculation to 400rpms?

[joecar]

Setting the dynamic air threshold to 400 disables VE... so your MAF is enabled;

SELBEN corrects the MAF, and VET replaces the VE (VET is calculated from corrected MAF);

when you set the dynamic air threshold back to stock (4000 rpm) you will see SELBEN and VET be the same (since MAF is corrected, and VET is calculated from corrected MAF)...

you will also see trims be close to zero (as you have seen).

[truethinker]

Ive just realized that my serial input is backwards. Lambda for bank 2 is actually bank 1. This matches my non-lean cruise fuel trims. Once bank 1 ltft shows a positive value the two wbo2's start showing a closer lambda value.

[truethinker]

Ahh okay, that makes sense. I'm still curious as to why one side would stay at such a different lambda.

[joecar]

I hope you had LC disabled while doing the Calc.VET MAF/VE tuning...?

[truethinker]

I hope you had LC disabled while doing the Calc.VET MAF/VE tuning...?

Yes sir. I only just enabled it.

[truethinker]

Joe, two quick questions.

First of all, I just wanted to bring up again my question about the difference between my two exhaust banks. My lambda values are different by as much as 0.030lambda with one bank always being leaner than the other. At times it seems that the LTFT's reflect this difference and attempt to correct it(successfully at times) without LC enabled. My average over the whole log is generally around 0.028 lambda difference without LTFT's; 0.011 with LTFT's enabled. I'm just wondering if this may be something I can correct in the tune or if it is a mechanical issue such as a weak injector or something. WBO2 sensors are in the factory locations.

Secondly, my lambda value is switching between 0.970-0.990. What can I adjust to bring this up to around 1.000?

Thanks!