My90Iroc

iTrader: (26)

I got my VE table tuned by using SD and open loop in conjunction with the wideband and the VE A/F error histogram in HP Tuners. I have a Z06 maf that I'm trying to now tune. I logged the dynamic airflow as stated in the sticky for maf tuning. The numbers seemed about right because they're a little higher than the numbers in my stock maf table. Now when I turn the maf back on and keep the car in open loop to try and tune my maf the a/f goes pig rich to the high 10's and low 11's even when just cruising. Even if I plug the numbers in from the stock maf table it's real rich.
What's the reason behind this?
Is there maybe a difference in the resistance of a Z06 maf and the stock f-body that needs to be accounted for?
I guess I can tune by just lowering the maf table down until the a/f works but there seems to be something I'm missing.
Any thoughts?

Billf6531

You're not missing anything. Since you changed the VE table, there is no longer any rational linkage between it and the MAF table. Just use the MAF AFR Error to correct the existing MAF calibration table.

ninobrn99

iTrader: (8)

quick questions for ya off topic. did your maf come with a screen?

SmokingWS6

iTrader: (1)

It simply needs to be calibrated, since you have the wideband interface you can go ahead and rework the table. once the ve and maf are calibrated your wideband should show exactly what your commanding in open loop.

My90Iroc

iTrader: (26)

Thanks for the responses, I didn't think I was missing anything. Back to tuning.


Yes it did but I removed it.

SilverSmoke

Do you modify your spark before after scaling the MAF utilizing OL SD tuning?

GuitsBoy

iTrader: (4)

It still dosnt make sense that it goes this far rich. If he's got his MAF fail set to 0, but is still logging the MAF Hz and Dynamic Airflow in a histogram, Based on dynamic airflow, the numbers should get him close when he punches them into his MAF table.

Would the proportional fueling numbers make a difference in open loop - MAF? Would the overcorrection be caused by the larger injectors?

I guess at this point the only thing to do is use the MAF error histogram.

My90Iroc

iTrader: (26)

Anyone? Anyone? I'm still way rich with the maf on and the MAF error table is telling me to take out a lot, to the point where I'd be in negative values if I listened to the histogram.

GuitsBoy

iTrader: (4)

Are you subtracting or using the multiply function? You want to use that multiply function, as the error is in a percentage, not an absolute. Cant go negative if youre doing a percentage! That must be your reason for overshooting!!! DOH! Use multiply the first time, then make your changes using "multiply by half" after that. Should dial you in pretty good.