Tune file changing VE wont fix 8:1 AFR on full throttle

[Moonshine]

Good Afternoon,

As the title suggests, I have a 04 GTO with torquer 2 cam, 3k rpm stall, long tube, .005 hone and forged pistons, 6.125 rods, small port on stock heads and 88mm throttle body. I bought the car with the cam, stall and headers and they had it tuned somewhere (not sure where) and it always ran a little rich. After I rebuilt the motor and added some the rest of the parts, then it got really rich on full throttle 8:1 and will stumble and stall at about 2k RPM when launching at the track. I have been using grok to help since this is my first time tuning and we got the startup almost correct and idle is now great but full throttle changes to the VE table won't seem to bring the AFR down. I did well over 15% drop in the VE tables where it shows rich but still not changing much on the AFR. Is there another area that can affect wide open AFR or is something in another part of my tune messed up and not letting it use the correct fueling for full throttle?

Any help is appreciated.

I know AI sucks at tuning but it is decent at getting new tuners up to speed and it is great at analyzing logs.

[nonnieselman]

I cant look at the tune since your using a newer version of EFI :(

[Moonshine]

I cant look at the tune since your using a newer version of EFI :(

Is it just because I opened and saved the file in V8? I still have the V7.5 if that will help

[nonnieselman]

Yea Read it off with V7.5 and post it again.

[Moonshine]

Yea Read it off with V7.5 and post it again.

Well my flashscan V2 will not work with 7.5 anymore. Firmware version on it is to new. I tried to update efi live to latest to see if that would fix it but I’m on the latest version.

[nonnieselman]

Dang.
Yea when you go to the latest version you loose V7.5.
Ill DL the new version on another laptop and check it out for you.

[Moonshine]

What tables control fueling during full throttle? if you cant open the tune I can at least get you screen shots of the relevant tables?

[robof16]

Read the description on B0120. You've got a funky looking MAF curve (B5001) and all that extra fuel could be coming from there. Be careful though, if the MAF sensor calibration is your problem, when you fix it, that VE table is probably dangerously lean if you get a MAF fail. Compare your MAF curve with the 04 ZO6 curve.
I didn't have a 04 GTO file to compare to...

[Moonshine]

Thanks, I will check and post SS of that tonight.

[joecar]

Post some log files showing the problem.

Are you getting any DTC's...?

[Moonshine]

24837
Here is a run at the track.
It loads up on so much fuel that on the second pass (I can't find that log right now) it started stalling at about 2k RPM and detonated fuel in the exhaust it sounded like.
This run I do have the log for it didn't do the stalling, but it still launches pretty rough and bogged down.

It use to give Long term fuel trim bank 1&2 errors but that went away after I adjusted the MAF several weeks ago. Most of the rest of the car is running pretty decent, initial crank still needs about 4-5% throttle for it to start and you have to hold it there for about 5-10 seconds before it will settle down.

Also just to be sure here is the injector table, does this look modified? curious if the previous tunner edited this table to try to fix an issue. 24840

[Moonshine]

Read the description on B0120. You've got a funky looking MAF curve (B5001) and all that extra fuel could be coming from there. Be careful though, if the MAF sensor calibration is your problem, when you fix it, that VE table is probably dangerously lean if you get a MAF fail. Compare your MAF curve with the 04 ZO6 curve.
I didn't have a 04 GTO file to compare to...

Edit

I had to reread your post, yes my MAF table is quite a bit different. I will start making slight changes to the MAF to see if that brings it more inline. 24838

Also im not sure if it matters but my B0120 table is in the Airflow section under Parameters and the RPM threshold for airflow calculations is 4000 RPM. 24839

[Tre-Cool]

you need to get a wideband installed, turn off closed loop fueling and either force maf off to tune the speed density fuel map or lower the high speed air rpm entry to tune the maf curve.

until then your just throwing shit at the wall.

I recommend the AEM x-series wideband units the 30-0300 will have an analog output that you can connect to your AD inputs to log the AFR & setup a ben file to apply as a correction to your maf/SD tables.

[robof16]

The 3 other guys that have responded know a lot more than I do but if I were in your position I would:
1. IF, you have a stock MAF in the stock location, copy the MAF table from a stock tune and set B0120 to 400 RPM. This would put you in MAF-only mode and you can drive it like that. PE works just like it's supposed to, etc.
2. Load a stock VE table. Yours is too messed up to fix IMO, and in MAF-only the car will only use VE if the MAF fails, or you fail it... maybe you should start all over with a the stock tune if a lot of other areas of the tune have been modified.
3. Get the wideband installed.
4. Start reading Joecar's tuning notes, look at the stickies "calc.vet" and "calc.maft"
I ran MAF-only until I added a turbo and got up to 5 psi. where I began the hit the frequency and flow limits of the stock MAF. I really didn't want to tune and run in speed density but it was the only way to turn up the boost. Turns out it is great, no downsides as far as I can tell. I left the MAF in place for the IAT function, and I still get semi-closed loop fueling everywhere I would want it, etc.

[dlatsch]

I am no expert here. I am chasing a rich condition at WOT as well, not as bad as your values though. One thing I am in process of evaluating is the O2 mV switch point. I set mine all to 450mV to see how that reacts in closed loop. Just something else to consider. If I'm off base, I'm sure I'll be corrected, again, newbie.