Ltft and stft at 0 but engine running super lean

[Gbgn1]

My commanded afr is 11.5 . My engine turbo. Whatever table I try to change i cannt get it to riches up.
Can someone send me in the right direction?


98 PCM. Intense tune. L67 with st2 cam, Northstar TB, 03 Northstar Maf

[5FDP]

Post the tune.

Ever try adding 5% to the MAF table to add fuel, thats the best way to do it.

[Gbgn1]

Sorry im a noob and thanks for the responds. You have a pic of the table you are refering too? The northstar Maf I have on it should tune the same as a stock maf?To post the tune ,you just export on a certain screen?

Thanks again


There is something odd I noticed when I set up the histogram for maf tuning. When it's at 0
the engine runs very rough and lean afr 18(rev it and it doesn't die and afr gos down)

When I get the afr to an acceptable say 12 or so the histogram is saying -100.(idles good but when u rev it ,its unstable leans out and dies)

[jimmyblue]

I think you should take a little step back, and determine
whether all of your instruments are trustworthy. In the
case of the wideband, that would include misfire and blow-
through (overlap) errors caused by exhaust air, as well as
any scaling issues with the software at both ends.

LTFT and STFT at zero means either deliberate open loop,
from the tuner, or fault induced open loop (things like O2
sensor codes, ECT out of range, etc.).

I don't know what histogram you are talking about but
I'm no fan of histogram based tuning for fuel; knock retard
and timing table tweaking is all I can trust that for (and
this, because I'm content with a little bit of conservatism
in the timing). Fueling, experience says there's too much
garbage in the data to trust its statistical rollup.

If I were you, I think I'd be trying old-school idle mixture
and low-RPM-mixture tuning methods. Tune to minimum MAP
for a given RPM and load, and you're certain to be giving
the motor what it wants (subject somewhat to timing; you
will take a few passes around that loop I expect).

Get it running shade tree style and see what your wideband
says.

[Gbgn1]

Thanks I'm going to get back to it in a couple days when it warms up