Lean at Part Throttle No Matter What I Do HELP???

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06-13-2023
Vaddy

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Lean at Part Throttle No Matter What I Do HELP???

So I am a pretty new tuner, so maybe someone sees something that I don't. The car is running in SD mode only forever, I turbo'd the car and apparently there's a exhaust leak where running closed loop makes the car very hard to tune. Anyways I show as very lean in some RPMs so I naturally multiply X% in the VE tables where it shows as lean. But somehow it gets leaner? The drivability goes bad and shows up to 150% lean but lowering the valves makes everything smoother but still shows as lean. HELP!

Attachment 133276
Attachment 133277
06-13-2023
gottogo

Please pardon me if I'm off base here.

Are you clearing the trims after making a change?
06-13-2023
Vaddy

I am not, is that something I should be doing? STFI and LTFT aren?t being used since I am in open loop only
06-13-2023
gottogo

I believe so.
If you don't clear the trims, then they are still acting based on the old values.
That's the way I learned to do it.
06-13-2023
KillboyPowerhead

Your LTFT's are showing 0% so I'd assume they're not being used, but just in case, along with resetting them you can also set the Fuel > O2 Sensors > Closed Loop Enable, Delay table to max values (32767 seconds), MAX ECT to minimum (-40) and the Min Map vs. Baro table to max values (2048 kPa).

Do you not have MAF sensor(s)? If you do you can tune the VVE and MAF at the same time.

If you still have an exhaust leak then you'll have to fix that or else it could be impossible to tune the air models, depending on where the leak is (maybe why you're super lean sometimes).

What size throttle body do you have? Just took a quick look at the tune but I noticed you have what I believe is the stock 72mm TB area in your tune. Also see that your VVE table only goes to 1.08 MAP/Baro ratio and 6400 RPM - how much boost are you making?
06-13-2023
Vbb1994

I dont know exactly what youre tuning with (wbo2 vs nbo2) but i will tell you its been my solid experience that overtly lean conditions (18+ afr) are just false leans.

Its actually ridiculously rich in gas and practically dousing the sensor.

I don't know if that's your case here or not, but also, filter your hit counts out. Sometimes those crazy hits only have like 4 hits in that cell, and something else more valid might have as many as 100+ hits in a particular cell
06-14-2023
KillboyPowerhead

Quote:

Originally Posted by Vbb1994

Its actually ridiculously rich in gas and practically dousing the sensor.

Just had a quick look last night but looking at the log again now; compared to mine (2015 Camaro, not turbo'd) I'm at 1.45 to 1.50 ms injection pulse width while idle (no boost) and this log is showing ~2.60 ms, so looking way rich. Likewise at 1:02.230 in the log, 2200 RPM @ 60 km/h I see 4 ms PW and 58 g/s VE airflow whereas mine is ~1.25 ms and 30 g/s VE airflow, similar fuel pressure (again, not boosted but guessing there's not much boost at 2200 RPM?). I don't reach 4 ms PW even at WOT and I'm seeing over 120% volumetric efficiency according to a few equations/calculators.

Maybe try lowering the whole VVE table in 10% increments or something and see how the car reacts, with more emphasis on the idle zones to get those dialed in first. Once the lambda is showing within 25% of commanded try getting up to ~2000 RPM in various gears, as steady on the pedal as you can be (cruise control) and dial in those areas of the VVE, smooth out to other zones, then repeat for higher RPMs, increasing 500 at a time or something. This is more or less what I did after installing Mace cams which made me 10 - 20% rich across the table.

May also want to set your cams to 0 everywhere when dialing in the VVE. The main/base VVE table you're adjusting is for when both cams are at 0 degrees, and you can't directly adjust the other tables (for other cam angles) without affecting the base table, so you'll want to get the base table dialed in first as best you can, then move the cams back to where they were/need to be.
06-14-2023
SiriusC1024

Why don't you get serious and fix the exhaust leak?
06-14-2023
Vaddy

Quote:

Originally Posted by KillboyPowerhead

Your LTFT's are showing 0% so I'd assume they're not being used, but just in case, along with resetting them you can also set the Fuel > O2 Sensors > Closed Loop Enable, Delay table to max values (32767 seconds), MAX ECT to minimum (-40) and the Min Map vs. Baro table to max values (2048 kPa).

Do you not have MAF sensor(s)? If you do you can tune the VVE and MAF at the same time.

If you still have an exhaust leak then you'll have to fix that or else it could be impossible to tune the air models, depending on where the leak is (maybe why you're super lean sometimes).

What size throttle body do you have? Just took a quick look at the tune but I noticed you have what I believe is the stock 72mm TB area in your tune. Also see that your VVE table only goes to 1.08 MAP/Baro ratio and 6400 RPM - how much boost are you making?

Didn?t have this lean issue before, it was only after I started trying to adjust VVE that this happened. Unless a larger leak occurred. Stock TB, and VVE table should go to 2.00 so that?s weird. Making 9psi
06-14-2023
Vaddy

Quote:

Originally Posted by KillboyPowerhead

Just had a quick look last night but looking at the log again now; compared to mine (2015 Camaro, not turbo'd) I'm at 1.45 to 1.50 ms injection pulse width while idle (no boost) and this log is showing ~2.60 ms, so looking way rich. Likewise at 1:02.230 in the log, 2200 RPM @ 60 km/h I see 4 ms PW and 58 g/s VE airflow whereas mine is ~1.25 ms and 30 g/s VE airflow, similar fuel pressure (again, not boosted but guessing there's not much boost at 2200 RPM?). I don't reach 4 ms PW even at WOT and I'm seeing over 120% volumetric efficiency according to a few equations/calculators.

Maybe try lowering the whole VVE table in 10% increments or something and see how the car reacts, with more emphasis on the idle zones to get those dialed in first. Once the lambda is showing within 25% of commanded try getting up to ~2000 RPM in various gears, as steady on the pedal as you can be (cruise control) and dial in those areas of the VVE, smooth out to other zones, then repeat for higher RPMs, increasing 500 at a time or something. This is more or less what I did after installing Mace cams which made me 10 - 20% rich across the table.

May also want to set your cams to 0 everywhere when dialing in the VVE. The main/base VVE table you're adjusting is for when both cams are at 0 degrees, and you can't directly adjust the other tables (for other cam angles) without affecting the base table, so you'll want to get the base table dialed in first as best you can, then move the cams back to where they were/need to be.

Got it, appreciate the explanation to why I need to lower instead. I just thought if you ever see lean conditions. You just increase the valves. IDK. But so far lowering the valves have really help
06-14-2023
Vaddy

Quote:

Originally Posted by SiriusC1024

Why don't you get serious and fix the exhaust leak?

I?m very serious. This kit does not fit on this car, this kit was from the V8 version of the Camaro that I made fit with 3D Printed Headers. The exhaust leak is probably around the headers which would cost A TON to re print the STAINLESS STEEL headers.
06-14-2023
gottogo

If you didn't have this problem before, go back to the previous tune.
06-16-2023
Vaddy

Update, was just a bad wideband sensor. Note if it?s 150% lean, sensor is trash
06-19-2023
Vbb1994

Quote:

Originally Posted by Vbb1994

I dont know exactly what youre tuning with (wbo2 vs nbo2) but i will tell you its been my solid experience that overtly lean conditions (18+ afr) are just false leans.

I guess i should've added to that, ANYTHING thats severely lean is usually false. Bad sensors included