MAF and Cyl Airmass Randomly Higher

[Nick912]

I just finished up installing a fully manual 4l80e with a 4000 stall converter in my 2011 Camaro SS (originally an M6). No changes made to the engine side of the tune, yet max MAF lb/min jumped from 50 to 63 at redline. MAF hz also jumped up by about 700. As maf is part of cylinder/spark airmass calculation, my airmass jumped up from a max of around .97 to 1.13. Also, even though the tune is set up running MAF only, the dynamic airflow calculations are also showing this jump (even though the volumetric efficiency number, kpa, and rpm are constant). This has also subsequently increased my injector duty cycle significantly. I don't have my wideband hooked up quite yet, but my assumption would be that I am running extremely rich. I could easily just redial in the maf after hooking up my wideband, but I am perplexed as to why this occurred and worried that something is wrong, and redialing in the maf might just be patching an underlying problem. If anyone has a clue as to what is going on here, it would be greatly appreciated if you could help me out.

Cam Specs:
.050":
235/248 .649/.615 111 LSA 109.5 ICL
Advertised Duration (.006"):
292/301

Current log and tune:
4l80e swap.hpt4l80 drive.hpl

Old setup log (MAF curve identical in tune)
MAF tune step 4.hpl

[Nick912]

Just got a few more logs with wideband and let me tell you... somethings seriously screwed in the tune and i can't spot it for the life of me. In the first attached log when going WOT at around the 6 minute mark, lambda went to a reasonable value (MAF is fairly off ATM), but then decided to go 50% lean, and the maf hz began dropping rapidly even though my foot stayed at 100% in it and throttle fallue stayed full-open (Car obviously felt like it fell on its face HARD). The second log again shows how the lamda will read at a reasonable level right when converter stalls up, but decides to go lean after running just fine for around a second or so... If anybody has a clue what could be going on here, and can either spot something in the tune or recommend me checking for broken sensors/parts, it would be greatly appreciated because i have been chasing my tail all day... $50 in gas and no results is quite a bummer

1st run (Didn't save tune): Screwed up.hpl

2nd: 4l80e step 4.hptScrewed up pt 2.hpl

[kevin87turbot]

Very likely just a bad MAF or some contamination on the MAF. Throw a new MAF sensor in it, or simply do an SD tune for now and try it again.

[Nick912]

I’ve got a can of MAF cleaner lying around somewhere, I’ll start with that. If that doesn’t help, SD it is for now. It’s just odd to me that even the dynamic airflow PID is reading the extra airflow as well, and also following the random airflow drops. To my understanding, that airflow number is based solely off of the SD table and MAP sensor value. That is the only thing I’m still trying to wrap my head around. Any ideas why this could be?

[Nick912]

Just copied in an old VVE table I had from a while back. Besides needing 20% more fuel at and around idle, everywhere else is within 1.5% on the rich side all the way to redline. Looks like I'm ditching the MAF, thanks for the suggestion