trims are wacked and actual AFR at WOT is no way close to commanded

[mvvette97]

I had the car tuned by a pro tuner several years ago. Just in the past year or so I just started getting brave at playing with the tune a little. All I did was add some air on startup to fix the start problem and then changed the WOT command AFR using a wideband. I was logging idle and cruise today and noticed that the trims are in the -8 to -12 at cruise and about the same at idle. I'm guessing it's been this was since he tuned it. I read about Auto VE tuning so I'm guessing I just need to do that but have no idea what to do. Can somebody explain how to do that? My engine mods are ported heads and comp cam 228/230 571/573 lift on a 112 and headers and LS6 intake. Here is my log I done and the tune that he done.

[WeathermanShawn]

What injectors are you running?

Table B4001 does not look stock?

[5.7ute]

Yikes. Looks like a quick IFR/maf tune to me.
Best thing to do would be read the AutoVE tutorial & ask specific questions on what you dont understand. This subject has really been done to death on here so specifics will have a better chance of recieving a reply. Also what injectors are you running?

[WeathermanShawn]

AUTOVE if you go Open-Loop.

In all honesty, I need to start promoting the multiple-authored CALC.VE Tutorial done just for Closed-Loop folks.. (See my sig for link).

I don't get any royalties for it, but the longer I assist tuners on this forum..the more I think it might be just the right process to start with those just starting and willing to actually read and follow it.

OP, you are already running closed-loop and MAF. Unless you have different injectors from stock, looks like that might have been inappropriately altered (hacked).

Let us know..

[5.7ute]

Unless you have different injectors from stock, looks like that might have been inappropriately altered (hacked).

Let us know..

My thoughts exactly. VE table looks like a quick cut & paste. Commanded fuel under PE is way off, more like the standard over rich settings. (I dont have a stock cal to compare it to)
If I was going to be tuning this I would be starting again from scratch, or at least comparing to a stock tune to see where the "Work" was done.

[mvvette97]

Oh I forgot I have the SVO 30s red tops

[WeathermanShawn]

Someone else will have to check your Injector Data. I would suspect the problem is there, because your MAF Calibration Table is actually stock.

When you said you [..did your Commanded AFR via a wideband..] I am a little confused. Did you log a wideband or did I miss it? What did you mean you 'set it'. Commanded vs Actual AFR are different.

Do you have a log with a wideband? Your Commanded AFR look rich. Why are you Commanding a 1.3 EQ Ratio (11.1 AFR)?

Let us know..

[5.7ute]

B4001 should be linear, hence the comments about the IFR tune.(some tuners modify this table to get commanded to actual AFR into line instead of VE/maf etc)
Set this to represent your injectors properly. Force open loop speed density as per the AutoVE tutorial & log wideband AFR, commanded AFR, TP, MAP,RPM, ECT, IAT & IBPW. I also log GM.DYNCYLAIR_DMA so if there is knock I can see where it is in the spark table.
Do not set PE to 1.0 EQ(14.63 AFR) as per the tutorial. Set it to something like 12.5 AFR so you have enrichment under PE.
If the car was dynotuned beforehand & made good power do a WOT log of actual AFR BEFORE making any changes. This will give you a ballpark of where you want commanded AFR to be under WOT conditions.

[mvvette97]

When the guy tuned it he didn't use a wideband. After I bought a wideband the WOT fuel was running like 13.8 so I thought it was too lean. Now the tune itself said it was commanding 11.7 but actual was 13.8. So I just kept lowering the table to where the wideband would set on 12.8 at WOT. I had to set those number in the tune that low just to get the 12.8 I was wanting. I have never logged the wideband but just watched it while driving, probably not safe but I'm still alive. haha. I have the AEM wideband and and have never found a way to hook it up to EFI Live.

[WeathermanShawn]

You can probably tell by now that altering your PE Table in order to get a Commanded AFR to read 'correct' creates further problems elsewhere in your tune. By neglecting to tune the VE Table and/or MAF your create big-time problems fueling at Idle and cruise. You need to tune airflow first.

OP, it would take pages to re-write all the tuning theory and methods. I would just respectfully ask you read the AUTOVE and CALC.VE Tutorial cover to cover. Read it for a month if you need to. You will slowly but surely see that you need to make sure your Injector Data is correct. Then you tune VE and/or MAF utilizing your narrowbands and wideband. It will eventually make sense.

Get your Injector Tables correct. Tune VE and MAF. Use a Wideband. Don't compensate the PE Table to hit Commanded AFR.

Thats all for now..