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

[kelleyperformance]

okay, i am stumped. i have searched for hours and talked to everyone i know with long time LSx experience as well.

to sum it up before (if at all) you read below- i have great fuel trims of no more than +/- 4 fuel trims, dead on PE commanded a/f VS actual a/f, but all the sudden the truck has begin to run anywhere from 11.9-13.1 a/f when out of PE (open or closed they barely change- note i have the STFT enabled for open loop though). SO, damn near perfect fuel trims and dead on PE, but way too rich all the time....

more details---

i have an 06 silverado ss, gen 3 6.0 iron block. i had just put a rebuilt completely different motor in. now i have been in and out of the hospital and work for months and my truck has suffered. i left the old tune from the last motor, which was close enough- been running with a 'raped' PE table as you all would call it for awhile now. fuel trims were way off, but hey the car ran close enough to 14.7 and the PE was fine.

heres my problem- i recently downloaded all of the awesome configs and histograms you all have made (thanks a ton by the way ) and got into spending some serious time making it all right. so i finally got the airflows dialed in, PE actual a/f is right on commanded, and the truck runs great. a few days pass, and i notice it starts running 11.8-13.1 a/f when in open and closed loop, all the time. here is what baffles me- the fuel trims dont EVER wonder past +/- 4.... but the a/f is way off. and since PE is dead on, im thinking the airflow numbers must be correct. no matter what i do- command the a/f to 14.7, it just stays the same. also, i replaced both b1s1 and b2s1 with the OEM bosh sensors about two weeks ago. i used the injector spreadsheet found on here for the IFR, and like i said the PE a/f is perfect. at this point i am driving a boosted 370 as a daily driver that is pissing gas away and it aint cheap PLEASE if you have any idea, post by all means please

ALSO NOTE i have checked to make sure the car IS NOT in PE all the time, only when its supposed to be- checked to make sure its not staying in open loop, its not- and have replaced the O2s.

[kelleyperformance]

okay here those are

[69lt1bird]

Why is your PE delay set to 100?

[69lt1bird]

Yep, all of the injector data is screwed up.

[kelleyperformance]

the delay is 100 cause i wanted activation based upon MAP and TPS only.

i have 70lb siemens injectors, fuel pressure is set at 60 psi.

all the other injector settings are set from a mail order tune, i just never changed them becuase im not too knowledgable on some of them

[kelleyperformance]

What part number are the injectors? tall or short? stock siemens injectors or modified?

they are the tall ones, flow rated 70 lb/hr @ 58 psi. - (stock not modified)

"At the standard fuel pressure of the LS1 and LS6 engines, 58 psi (4 BAR), these injectors flow 70 lbs/hr (8.8 gps). 60 lbs/hr at 43.5 PSI (3 BAR), and up to 85 lbs/hr at 87 PSI! In addition, these units are high-impedance; making them compatible with most ECUs including the GM factory PCM and ECM used on the LT1, LS1 and most other GM V8 applications."

heres the link to the product page as well

[kelleyperformance]

you need to correct the injector settings in your tune as they are not set up correct and will keep causing fueling problems for you.

which settings in which tables? i dont know much about the injector settings to be honest

[kelleyperformance]

okay so i gave changing those tables a try... are these any better??

[69lt1bird]

The voltage, min pulse, short pulse adder, default are all wrong. See if you can get the data from who you got them from or you need the info from Greg Banish's DVD.

[kelleyperformance]

The voltage, min pulse, short pulse adder, default are all wrong. See if you can get the data from who you got them from or you need the info from Greg Banish's DVD.

i havent any knowledge on this DVD... what is it and where do i get it? so even those new numbers are still wrong??

[kelleyperformance]

okay, ive tried everything. spent hours changing injector settings, retuning, etc. truck runs better but the a/f issue is still present. sometimes from ignition cycle to cycle it will just 'switch' to the correct stoich a/f. the truck appears to believe its running damn near perfect on stoich, but is in fact actually rich.

[kelleyperformance]

no one has any other ideas...??

my thinking is this- even if i had 20 lb/hr in for my IFR, put the car in closed loop and whats it going to do? max the fuel trims out in an attempt to get to stoich a/f ratio. and if things are even relatively close, the car is STILL going to run close to 14.7. at the end of the chain, the O2 functions always rule on top... SO throughout all the calculations the PCM does, whether it deems one failing or all of them (but the O2's) failing, it remains to adjust fueling to best match stoich.

yet despite all of this, my truck remains 12.1 in closed loop and in open loop. yet in PE, commanded A/F is dead on with actual A/F... which is why i feel the inj tables dont have alot to do with this particular issue. i even changed ALL the inejector tables drastically, and then proceeded to retune the other related items (MAF, SD, etc etc). no matter how perfect i got the actual a/f while adjusting in open loop (no maf), as soon as i plugged the maf in, it went rich right to 12.1ish. but obviously now the fuel trims were at least 12% or higher off, because its thinking 12.1 is stoich.....

[Delft Calais]

It looks like your wide band/sensor is dodgy to me, your fuel trims are decent, your commanding what you want and your 02's basically agree with it.
If you have a look at your wide band readings they dont change and neither dos your afr error because your wide band data is corrupt.

[Delft Calais]

your injector data is wrong but its not your drama here.

[kelleyperformance]

my wideband was the first suspect, its all been replaced and calibrated.

[69lt1bird]

Under Engine - Airflow - Electronic Throttle.

Why was the Pedal Desired Area changed?

[kelleyperformance]

Under Engine - Airflow - Electronic Throttle.

Why was the Pedal Desired Area changed?

its not changed. i had this problem with PCMs bricking because when i opened my older files (pre-ETC table capability) they came up red, like theyd been changed but id never even clicked them let alone seen them. so i just leave them alone and everything works ok.

[69lt1bird]

I was trying to compare you file to a stock 06 Silverado to see what may be different that could contributing to your problem and that one jump out at me.

[kelleyperformance]

yeah that is an upsetting subject with me... two PCMs

[69lt1bird]

what is the stock pcm/tune from?