Bink

Okay..I see what you mean.
Endres is talking about a hypothetical, simplistic algorithm for pulsewidth calculation. He is defining a lookup table "B" as an adjustment to the base pulsewidth. In this hypothetical an increase in O2, in the exhaust, results in a fuel reduction via lookup table "B". This would result on an increased AFR.
Either he has created an inaccurate hypothetical example or he knows of a "special circumstance" lookup table ( one in which you would want to further lean out an AFR - above the measured AFR).

Regardless, this is not the normal functioning of a closed loop system. Normal is:
AFR above stoich -> add fuel.
AFR below stoich-> pull fuel.

As far as the O2 Sensors are concerned there is no such "False Lean". It's either lean or rich.

Target => Stoich

Robert56

iTrader: (2)

Bink, good insight. I think your right about Endres, as I tried to figure the math out in real world tuning and I was lost, couldn't figure it out. Furthermore, hypothetical alogrithm is maybe right on, until proven otherwise.
In conclusion, (like others said, but I have to know why) mongo overlap causes false lean (named because tune with normal cam would be allright?) and adds fuel accordingly, making idle problems even worse (compared to non pcm controlled set-ups). So, dump the maf and 02's and go into true SD mode with big cams?

Bink

Open loop tune with or without the MAF. Then scale the MAF as neccessary to achieve 14.7 at idle. You don't need to dump the MAF. The VE (DYNAIR) and MAF should be synchronised so that the MAF isn't reporting too far above, or below, the DYNAIR values.