PLEASE HELP: Incorrect a/f in closed loop on LQ9

[kelleyperformance]

the latest software as of Dec 09 for the VIN of my 06 silvy

[69lt1bird]

Do you have the stock truck tune file? The reason I am asking is, the stock 06 tune I pulled from the repository has different ETC settings than yours and maybe that is contributing to the issue. If the PCM thinks or the TAC thinks the throttle is out of sync or settings are not spec, maybe the fueling is hitting a different cell that is is supposed to be in.

[kelleyperformance]

no, the whole thing is with HPT with the ETC values... it doesnt interpret them correctly. on the gen 3 trucks if you so much as even click a cell in the ETC table it bricks. there would be no way for me to even accidentally change these settings, it would just brick

[kelleyperformance]

okay i got the banish values all in place, tomorrow i will be redoing my exhaust just to make sure there are no leaks, and then going to retune the airflow values. i already went over all the vaccum routing to make sure thats good, so im hopeful about this. what do you all think of these inj values now?

[69lt1bird]

That should help with the right data in there. Good Luck

[kelleyperformance]

okay so i found two exhaust leaks, fixed those... then flashed the tune with the greg banish injector values in, spent all the time retuning the airflow values. runs MUCH better and smoother, and my little hesitation at lower RPMs into PE is gone. however... still running rich with +1-2 fuel trims.... i give up lol i guess i will just suffer my MPG forever

[bullygoat]

Are you tuning your MAF sensor? From the sounds of it, you've tuned the VE then you're plugging the MAF back in and thinking everything will be good without tuning the MAF sensor? Have I got this correct or did I misinterpret what you wrote?

[kelleyperformance]

all tuned and settled down- SAME exact issue. i give up

Are you tuning your MAF sensor? From the sounds of it, you've tuned the VE then you're plugging the MAF back in and thinking everything will be good without tuning the MAF sensor? Have I got this correct or did I misinterpret what you wrote?

lol no, cant say that im that stupid...

[bullygoat]

Well we need a log to see what's going on. Without that, it's hard to say what could be causing your problem.

Edit: Just looked at your tune. That VE table can't be correct. You don't have that great of a change between idle and wide open throttle. What are the complete specs on your motor? Heads, Cam, exhaust?

[kelleyperformance]

Well we need a log to see what's going on. Without that, it's hard to say what could be causing your problem.

Edit: Just looked at your tune. That VE table can't be correct. You don't have that great of a change between idle and wide open throttle. What are the complete specs on your motor? Heads, Cam, exhaust?

forged 370, final CR of 9.7:1. LS2 CNC'd heads (started from GMPP pieces), LPE GT2-3 cam, crane 1.8 rockers and high rpm lifters, magnacharger MP112, about 8 lbs boost, 1 3/4 LT headers w/o cats, 70lb siemens injectors, dual in-tank walbro's.... that what you needed?

im now down to the PCM that was installed around when the issue began... i bought it off someone who SAID it was new, probably pulled it out of a warranty room at a dealer so the new one comes today or tomorrow. ill keep you posted for those with any interest in this lol. everyone has posted a logical reason why its rich, but i dont think anyones really read into what im really saying.... the PCM, thinks stoich is between 12:1-13.5:1, meaning no matter how perfect my MAF table, injector data, VE table, etc etc is, its going to always add fuel because it believes the truck is lean when in fact its stoich.

i have a 950 RWHP Z06 in the shop right now, and who ever tuned it must be a very confused man... all the data is SOOO SOO wrong. BUT none-the-less of having maxed out fuel trims, guess what- it runs around 14.7-15:1.... just trying to prove my example

[MStefak]

So your commanded AFR wont go past 12:1-13.5:1 ? Even though yoiu have it set to 14.7 ?

[LSxpwrdZ]

So basically you are saying that it is commanding a richer a/f ratio than stoich? I've seen my dad's 05 5.3 Silverado do this by commanding a 1.0 equivalence ratio but it end up being 14.2 or 13.8:1 afr. What I've found it to be is the alcohol content table. When I tuned his truck I took that table and made every value in it 14.681 so that it could not correct for alcohol content and when i finished tuning it I then copied the tables back to how they were from the factory and highlighted the first 3 cells and made them 14.681 so my readings wouldn't change. Around here in KY we don't have enough alcohol added in our gas for it to really read but for whatever reason it did.

Now I know this may not be your problem but it is something to look into for sure!

To determine if this is your problem go do a log of Commanded HiRes AFR and also Equivalence Ratio. If the Equivalence Ratio is 1.0 and your commanding anything other than 14.68 then your truck is picking up alcohol content in the fuel and is adjusting the Stoich AFR for the alcohol content.

EDIT
With all that said I went back and looked at your log and that is not the case. If your narrowbands are working right which it looks like they are and your wideband isnt reading the right AFR then I would think your wideband is fubar'd haha

[6.0_VHO]

are you unplugging your MAR to tune VE? the IAT sensor is also on this plug and if you unplug it, you will run pig rich. if you tune your VE table that way, when you plug the MAF/IAT back in that's where it'll be.

[kelleyperformance]

okay so update... i have spent all day on the O2s, checking resistance, wiring, changing the sensors AGAIN... and it all checked out perfect. HOWEVER- i did find something interesting... the fuel mode cell is at 17 at idle, which seems weird to me seeing as the max is supposed to be 16. also, at a higher throttle they go into 20. even if the PCM did have modes that high, it would be completely the wrong mode for the very low airflow amount its actually seeing. this would also explain the perfect fuel trims yet rich a/f, because its in a mode for much much more air. so somehow the modes got messed up, and i cant figure out how and what to change. please please any ideas or knowledge would be much appreciated.

So basically you are saying that it is commanding a richer a/f ratio than stoich? I've seen my dad's 05 5.3 Silverado do this by commanding a 1.0 equivalence ratio but it end up being 14.2 or 13.8:1 afr. What I've found it to be is the alcohol content table. When I tuned his truck I took that table and made every value in it 14.681 so that it could not correct for alcohol content and when i finished tuning it I then copied the tables back to how they were from the factory and highlighted the first 3 cells and made them 14.681 so my readings wouldn't change. Around here in KY we don't have enough alcohol added in our gas for it to really read but for whatever reason it did.

Now I know this may not be your problem but it is something to look into for sure!

To determine if this is your problem go do a log of Commanded HiRes AFR and also Equivalence Ratio. If the Equivalence Ratio is 1.0 and your commanding anything other than 14.68 then your truck is picking up alcohol content in the fuel and is adjusting the Stoich AFR for the alcohol content.

EDIT
With all that said I went back and looked at your log and that is not the case. If your narrowbands are working right which it looks like they are and your wideband isnt reading the right AFR then I would think your wideband is fubar'd haha

wideband is okay, its all brand new and ive tested it all as well. even swapped the sensor with our dyno sensor (same model) and its exactly the same. also, im assuming your dads truck is is the flex fuel motor (Z), and this is equipped with the fuel composition sensor. the non-ethanol trucks (that ive ever seen) dont have a composition sensor. so i assumed that wasnt part of the issue, but hell at this point it could be anything right ? thank you for the help, i will try it, nothing to loose

are you unplugging your MAR to tune VE? the IAT sensor is also on this plug and if you unplug it, you will run pig rich. if you tune your VE table that way, when you plug the MAF/IAT back in that's where it'll be.

i have my IAT sensor in my manifold, so i have that covered. trust me, at this point i have looked at every damn detail so so many times id hope i didnt miss anything like that lol

[kelleyperformance]

so i tried forcing the a/f table to 14.4 all across, and i thought it fixed it. its been two days or so, and at least 25 ignition cycles and it worked perfectly each and every time. but tonight it acted up again :facepalm: this is kicking my ass, somebodys got to have seen something similar before, please PLEASE chime in

[Delft Calais]

any progress on this at all?