Thanks for the feedback.

Quote Originally Posted by Terminal_Crazy View Post
I’ve been tuning for ever in SD with a wideband.
I see lots of very lean data on stabbing the throttle open.
This is why I went to MAF after learning how the pump shot works. kur4o did a bit of a write-up on it here.

After sleeping on it and looking with fresh eyes I discovered something funky with fueling. It's easier to see if you download the eehack log and step through starting at frame 19070. afr number below is commanded, not measured.

19072 maf : 149.77 afr : 13.5:1 ipw : ~11.4ms
19073 maf : 153.09 afr : 13.4:1 ipw : ~10.4ms
19074 maf : 155.26 afr : 13.3:1 ipw : 9.89ms
19075 maf : 159.31 afr : 13.0:1 ipw : ~9.67ms
19076 maf : 162.92 afr : 12.7:1 ipw : ~9.5ms
19077 maf : 170.84 afr : 12.7:1 ipw : 9.21ms
19078 maf : 173.99 afr : 12.6:1 ipw : ~9.18ms
19079 maf : 178.66 afr : 12.7:1 ipw : ~9.15ms

This pattern of rising airflow and falling ipw continues until I shift into 2nd. In 2nd it's a bit different, but I think what I'm seeing is the pump shot decaying to zero? This leads me to think my MAF tuning was skewed way lean at higher flows by the pump shot adder. This never occurred to me because I seemed to recall seeing lean numbers running SD also, but that could have been at tip-in. I guess the pump shot works in closed loop? Hooda thunkit?

So steveo was right again - she wants more fuel!

I guess I'll have to see about adding the pump shot params to my xdf and do more logging with it disabled.