Engine goes mega lean when it enters closed loop

[rindoze]

This is an E67 ECM manual car. When in OL I am mostly rich, with some lean spikes that lead to random misfires being thrown. Car drives pretty good other than those random stumbles, but once warmed up and in closed loop, it suddenly goes super lean. Car is just coughing and sputtering, just wants to idle and not rev.
I've upped the whole VVE table +25% 3 times now, each time with very minimal change noticed. Not sure why there would be such a huge difference between open and closed.
Drive log is in OL, 7 and 8 are each +25% to VVE. I also upped the idle speed and relaxed misfire detection on 7,8.

drive.hpl7.hpl8.hpl

[edcmat-l1]

This is a screen shot from your open loop tune. Every time you give it some RPM it's dead lean. So yeah it's going to add a bunch via the trims. I'd say you probably have something off in the tune but you know, no tune posted so....

[rindoze]

Here are the tunes before and after adding a ton to the VVE which line up with the logs.
This is a turbo straight 6 with 3 bar map. One interesting thing is the injector flow rate vs pressure from the factory is pretty flat unlike the v8s.
L28Original.hpt

[edcmat-l1]

You haven't failed the MAF. It's not in speed density. Adding to the VVE isn't doing anything really. And you're not logging MAF Hz so you can't dial that in using the posted data log.

[rindoze]

I posted the wrong tune for the VVE update, by the final log posted it was up 2-3x what was in the tune. This should be having a significant impact right? As the logs show it wasn't doing anything to help stft. I tried to bump the MAF curve 10% but then it just was reading 10% too rich and was popping out the exhaust.

[edcmat-l1]

I posted the wrong tune for the VVE update, by the final log posted it was up 2-3x what was in the tune. This should be having a significant impact right? As the logs show it wasn't doing anything to help stft. I tried to bump the MAF curve 10% but then it just was reading 10% too rich and was popping out the exhaust.

None of that makes sense. Post a tune file and a data log taken with the posted tune file.

[rindoze]

I agree, makes no sense. Here is a tune with the VVE values from run 8 L28+VE.hpt
Run 7 was that x.75.
From what I can tell, the leans are in transient zones on log 1, which would line up with where VVE is used. And VVE would be mainly used in closed loop when everything is lean. But adding a ton to VVE did not really do much as seen in log 7 and 8. It actually started throwing a MAP sensor error when I scaled them up so much, which I assume is because they are so out of whack. My MAP is reading correct 100kpa with engine off and never threw a code before. I though it may have been something related to variable camshaft as I only adjusted the 0 angle tables, but the VVEs actually get even greater with cam angle automatically.

[edcmat-l1]

I agree, makes no sense. Here is a tune with the VVE values from run 8 L28+VE.hpt
Run 7 was that x.75.
From what I can tell, the leans are in transient zones on log 1, which would line up with where VVE is used. And VVE would be mainly used in closed loop when everything is lean. But adding a ton to VVE did not really do much as seen in log 7 and 8. It actually started throwing a MAP sensor error when I scaled them up so much, which I assume is because they are so out of whack. My MAP is reading correct 100kpa with engine off and never threw a code before. I though it may have been something related to variable camshaft as I only adjusted the 0 angle tables, but the VVEs actually get even greater with cam angle automatically.

No, you're not making sense. The data log posted is lean in the same area during open loop same as it is in closed loop. You're not doing it right. Need to keep it in closed loop, fail the maf and adjust the VVE according. Then turn the MAF back on and dial it in accordingly. It is a perfectly solvable problem. There's no use trying to tune the VVE without failing the maf.

[rindoze]

I tried to fail the MAf, and I get P0068 as soon as I touch the gas and then the throttle pedal is disabled. I disabled the DTC for P0068 but then it disables the throttle pedal.
Here is the log and tune. I tried throwing a massive amount at VVE but always the same result, throttle pedal disabled and car barely idles.
Attachment 140005L28SD.hpt

[rindoze]

Tried again but this time removing from the VVE. It no longer throws P0068, and revs, but is still showing lean. This log is just me idling in neutral.
mafFailed less VVE.hpl
L28SD2.hpt

[rindoze]

I added 1.1x then 1.1x again and again. On the second 1.1x the car drove fantastic, misfires were gone, but it was showing lean all over again. When I did the the 3rd 1.1x it felt worse, had some stumbles again. I don't have a log for the 3rd 1.1x because laptop died. But here are the first two. Starting to look like something is wrong with my O2.
mafFailed less VVE+10.hpl mafFailed less VVE+10+10.hpl

[SiriusC1024]

B2S1 isn't being logged.

[edcmat-l1]

B2S1 isn't being logged.

Pretty sure that vehicle doesn't have a B2S1.

[edcmat-l1]

You are kind of all over the place with the "Added to this one, took away from this one".

Pick a file, make a change, post a data log.

Looking at one of the files it looks like you need to start with multiplying the entire table by 1.2. Do that, run a data log and post that data log.

You should also have a fuel pressure gauge on the vehicle that you can read from the driver's seat as you operate the vehicle. Without that you shouldn't be making any changes at all.

What's been done to the vehicle to require an additional 20-30% of fuel? That sounds like injectors have been changed, major engine mods, etc. That or you're low on fuel pressure.

[SiriusC1024]

Oh it's an I6 in the V8 forum lol.

[GHuggins]

Are fuel trims agreeing with your wideband??? There's no way you're running good or it feels good being 45% lean on trims.

FWIW these are oddball OS's. If you're not running or have removed post O2's then you might want to reinstall then recheck things. They use post O2's for precat O2 fuel verification so it's possible pre O2's are skewing. It was rare, but ran into that problem about 4 different times on these back when it was common to play with them.

With it being turbo charged you might want to slow down the O2's too. Timing and everything is jumping around. That alone will skew fueling. I assume engine and valve train are good?

[rindoze]

Yeah its an I6, the I6 forums were pretty dead so posted in here. Whats been done is this is an Nissan L28 engine with ALL the EMS of a vortec 4200 attached to it (sensors, injectors, throttle body, pedal, everything). I'm not worried about fuel pressure, I have a camaro Zl1 pump feeding this and expect around 350whp when deep in boost.
I'm using the original MPV1, non pro, so can't hookup a wideband. Only running the precat O2, wiring harness I got had the second one chopped off and I'm used to deleting them on V8s. I'll try to get the wiring for one and see. I also ordered another O2 bung, I am running the O2 ~1.5ft after the collector merge and 1ft before the turbo. I'm going to add a bung in the collector to see what it says.
mafFailed less VVE.hpl is the log for tune L28SD2.hpt. The logs of mafFailed less VVE+10.hpl mafFailed less VVE+10+10.hpl are L28SD2.hpt with whole VVE x1.1 and then x1.1 again. So VVE+10+10.hpl is a log with 21% more fuel than mafFailed less VVE.hpl.
If you look at mafFailed less VVE+10+10.hpl I'm idling for about the first minute. At ~24-52 seconds with the car sitting idling the O2 is oscillating between full rich and full lean when nothing else is changing so my guess is the O2 reading is wrong.

[edcmat-l1]

I'm not worried about fuel pressure, I have a camaro Zl1 pump feeding this and expect around 350whp when deep in boost.

Just from a diagnostic point of view, this is counterproductive. I never assume anything. I always cover my basics. Thinking "It ain't fuel pressure the pump is brand new" will 9 times out of 10 bite you in the ass. ESPECAILLY when it has all the classic symptoms of low fuel pressure. Ignore the obvious at your own peril.

[GHuggins]

What Ed said but I've got more questions after reading your last statement. So you say you're using the Nissan engine with the 4200 GM intake manifold injectors throttle body pedal and so forth. Are you using the O2 that was originally in the Nissan or is it the one for the GM operating system? You need to be running the one for the Trailblazer. Oxygen sensor placement is going to play into this a lot too now. Also is the Nissan engine running a fixed intake cam with variable cam exhaust like the gm? Is there a reason why you didn't just use the whole Chevrolet 4200 motor? Only saying because you could literally change the mechanical timing of the intake cam and those were some freaking badass running Motors.

[rindoze]

Just from a diagnostic point of view, this is counterproductive. I never assume anything. I always cover my basics. Thinking "It ain't fuel pressure the pump is brand new" will 9 times out of 10 bite you in the ass. ESPECAILLY when it has all the classic symptoms of low fuel pressure. Ignore the obvious at your own peril.

I agree, and was thinking the same but its now looking like O2 issues to me. Before I put this engine in the car it had a turbo LS in it which I sold. The pump stayed in the car (its in the tank) and that engine was putting out 700hp+.
When I was adding a ton to the VVE before, I could tell it was getting more fuel to the point where it didn't want to start and there was lots of fuel in the exhaust. I heard that being real rich can clog the O2s and make them read lean, but if thats the case its odd that it comes and goes.