VTC_WS6

iTrader: (9)

IIRC, I followed a detailed discussion on this topic at EFILive.com, bottom line was the way the PCM software was written, the PE effect is only a positive one, it cannot remove fuel even with negative LTFT's remaining.

joecar

I wouldn't set fueling to 1.00 everywhere... I would run the normal fueling during tuning to prevent going lean (and causing damage)...

the commanded AFR is present in the AFR pid, so you're not chasing an ever changing AFR.

Bowtie316

iTrader: (1)

Thats interesting, so just shut off closed loop, LTFT and STFT and start loggingand tuning? Any drawbacks doing it this way.

BLK02WS6

iTrader: (2)

Been doing it that way for years - only difference is that I tune the VE table that way first, then the MAF table (unless staying in SD)... I always set my OL table and my PE table to values that I want to obtain first (sane and safe values), then correct the VE and MAF tables to reach those settings... then, once my actual equals my target fueling, I fine tune to obtain max torque and HP by making small changes to the PE table and the spark table.

joecar

When you flash clear the trims (your tuning tool might already do this for you), and start logging...

first do VE (with disabled MAF), and then do MAF (with disabled VE), like BLKO2WS6 said...

before starting make sure PE will enable (be careful with truck tunes, they enable PE at 90% which is too late), and make sure it will be suitably rich to avoid damage; then during the log make sure that wideband shows PE enabling at load and that it fuels sufficiently rich...

to avoid transitions from OLFA to PE, make PE flat and make the last few columns in OLFA same as PE (but those transitions should not really be too much of a problem in most cases, so you don't really have to do this).

joecar

And keep in mind that the front NBO2's are good for about 70K miles... and then you should replace them anyway (even if they seem good).

Like Ed said, negative trims will never pull fuel, ever.

Bowtie316

iTrader: (1)

10-4, yeah I always start with tuning VE in SD. And yes set OL and PE tables to what I wanted first. I clear trims each time I flash a new calibration, I have made that mistake before.

Would it be a good idea to add a certain percentage to the VE table before running in OL the first time to keep it on the safe side? Or would it be better to add a percentage to the OL and PE tables?

spy2520

iTrader: (3)

I had the opposite problem one time when i had the "RPM threshold for Airflow Calculation" set to 400. No maf = no start.

joecar

Particular mods will increase VE a known amount... if you bump up the VE table the known amount (rather than OLFA and/or PE), then as you tune you only need to edit the VE table (minimizes the number of edits).

joecar

Probably because the MAF DTC did not show up.

Gatsby

iTrader: (7)

Hey everyone,

Since there always seems to be threads with no apparent resolution I wanted to revive this thread and let everyone know how it went.

After taking most of the advice in this thread and doing more research I played with the tune more. I recalibrated my WBO2, retuned my VE table (which is now within +/- 3 and looks smooth), and then turned the MAF back on (for the MAF tuning portion) and set the OLFA table back to stock. I started the car up with crossed fingers and voila! Even with a MAF table that is not yet tuned the car ran amazing! I'm sure I've got a lot of fine tuning left and I'm still learning a lot, but the throttle response is great, no hesitation anymore, no bogging, all around great!

Moral of the story? Listen to the people in here, do your research, and be PATIENT! I can't tell you how many times with tuning i've felt like selling the damn car, but in the end, I love it again.

Thanks to everyone that lent their advice.

BLK02WS6

iTrader: (2)

Glad it went well for you!