Lean spike mid pull

[askkmb]

Hello, im tuning an older truck that has a 6.0/6l80e turbo deal. E67 ecm and t43. 2009 TBSS O.S.

Currently trying to dial in vve but i randomly get a lean spike. Its not always, just randomly. As far as i can find out its not that the fuel pump is sucking air or anything like that and rather that the ecm commands it to cut off fuel. Torque management doesnt seem to interfere. What i notice is INJ pw drops to 0 as well as Volumetric Efficiency drops to 0. If i keep it floored it comes back right away and pulls like normal but it has that lean spike. Cant figure out how to attach a datalog. I can send via email if anyone wants to take a look

[blindsquirrel]

I believe this is what it'll turn out to be: https://www.google.com/search?tbs=li...ers.com+desoot
Do some reading.

screenshot.27-08-2020 01.24.55.png

To attach files, click the 'Go Advanced' button and scroll down.
screenshot.27-08-2020 01.31.48.png

[askkmb]

Enrich desoot is already disabled so i dont think its that unless its doing something in the background that i dont see. But its acting very similar to what i see described in the link you attached.

And even going into advanced i dont see an option to attach the log. The site looks updated and different from before. But i can send through email.

[ZincGT]

0 out prediction coefficients

[askkmb]

All of them? Base, Current, Old and Corrected are the 4 that are already zeroed out but the other ones still have values in them. All the Map and TPS ones

[RobZL1]

Yep, zeros in the MAP and TPS tables, too. Seems like this is always due to either the desoot or the prediction coefficients.

[askkmb]

That did the trick. Thanks guys

[askkmb]

Well i thought the issue was resolved but apperantly not. Enrich desoot is disabled and all the prediction coefficients are zeroed out like suggested and it stil keeps doing it. I made a log where it happend twice in the same pull but still cant figure out how to attach a datalog. Any ideas?

[griffincox]

Make sure to attach a tune file also. All the airflow is calibrated and smooth?

[askkmb]

VVE is dialed in. Running SD without maf. Double checked everything in the tune and I can't figure out what's going on. I must be overlooking something.

[RobZL1]

Is this a custom OS with true SD, or are you running VVE only? I wouldn't run VVE only. Lots of odd stuff could happen there.

Should be fine if you have an ECM that was early enough to apply the SD OS, though. If VVE only on the stock OS, odd stuff is not surprising in my opinion.

[askkmb]

ECM is a 2009 E67. Dont see an option to upgrade to custom OS. One thing i saw just now is under OS the setting that says Manifold vacuum boost is not applied. Could that cause issues?

And how should i go about this? Would using a MAF sensor resolve this issue? Which maf could i use for enough range on a boosted setup?

[griffincox]

I would definitely use a MAF. The system was designed to rely heavily on it. You could try an 07 TBSS OS or a 09-12 CTS-V. Some of them have custom OS available.