I am getting STFT on WOT (Open Loop) and i cannot work out why this is happening - I am trying to resolve a lean condition issue and it is not helping the issue.
Note- i planned on uploading log and tune file but the option to attach is missing??
GOT it, i was not on the "full site" mode
Last edited by tyrefryer; 12-20-2018 at 09:33 PM.
if you go back and edit your post and go to the advanced edit screen and scroll down to manage attachments you should be able to upload files and attach them from that menu.
You can disable the trims via the scanner special functions if you need too. I forget off hand how it's worded, you can click LTFT off and the fuel trim learn off and they will stop working.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
I have had this with Australian early E38 PCMs a few times. I couldn't stop it either.
its not a correcting STFT influence, its a set -3% STFT at WOT. I personally just accepted it and tuned with it their. its a constant so in theory you should be able to tune around it, but I actually doubt it is influencing the injector PW despite logging in the scanner.
as for your lean condition....
zero out your PE delay RPM.... especially in a PD car you want absolutely no delay going into PE or allowing enrichments....
set your BE EQ ratio to what you desire.... perhaps 1.2 instead of the 1 its at now.
if youre injectors are bigger that 60lb/hr you'll also have issues. if that's the case you'll need to double stoich, halve the IVT terms and set IFR to 50% of actual... then redo the VE tables.
if theyre 60lb/hr or smaller ... try attached edit.tune_edit.hpt
This is an early Australian e38 ecu, yes.
This car tuned up fine about 4 years ago but after killing a 6L80 and replacing it the test drive popped up with the lean condition, funnily enough only on one bank.
I am thinking maybe bad plugs or blocked cat (already had injectors cleaned and checked out ok)
I know the fuelling on the car was spot on prior to this so its annoying as to why that 3% is there now. I doubt its my issue but I just wanted to get rid of it.
Also the injectors are 60lbs so I didn't have the mass air issue.
I will try your edit Luke - I can see the reasoning behind the changes you've made - looking at the log again when it hits the lean spots it is also spark reducing big time.
Starting to look more like a TM or Supercharger Limiting issue.
I am also starting to think that maybe the issue has been created when I pulled the tune to make some minor adjustments its preset a few things that weren't available back when i originally tuned this vehicle!
The BE from memory wasn't an option 4 years ago and if it were i certainly wouldn't/shouldn't have left it at 1.0 - the commanded AFR is still at 12.0 - 12.2 on boost MAPs though.
I also don't think all the supercharger limiters were in there when i originally tuned it.
I've even seen this recently on early E38s that have come in entirely stock. I assumed it was a software glitch causing the open loop STFT to default to -3.1% instead of 0%. the ones I've done never seem to pull 3% fuel in open loop when comparing VE table values to other cars with similar combos.
what size are your injectors?
the commanded AFR is 12.2 because you're PE EQ ratio is 1.2 or 12.25:1
where and when is your lean condition and how lean?
The injectors are 60lbs.
Could be a glitch - I have seen a couple that read spark knock retard at all RPMs when really it wasn't retarding at all.
I have attached 2 screenshots of WOT pulls - i haven't put it back on the dyno to check the AFR but its lean enough to throw the narrowband into reading lean (~14.7) and i can physically feel the lack of fuel.
If its only hit with roughly 50% throttle it pulls a lot harder and doesn't lean out
I would try those PE and BE edits.
also log all the fuel and ETC torque management PIDS you can to rule that out also.
Can now confirm - that stupid 3.1% STFT on the early LS2 HSVs is real!
This particular car has gone about 4 runs and got the AFR to a very consistent and happy place.
Did one final run and BAM 3.1% showed up, my AFR is now all around 3% out.
This is easy to work around IF it happens during the tuning phase - what happens if i were to have not done that final run and tomorrow the car decided to throw away 3% of fuel for no reason.
This must be a HP tuner issue surely?
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