Gary looked at the logs and didn't see anything that stood out which leads me back to the problem being mechanical, which I assumed. I.just can't figure out what's different.
I figured Maybe the cap coming off the air filter would cause an influx of air and cause the fuel cut. Then, the excess air would affect the tune. But, that's now fixed.

 

when you said two tests and followed with what you wrote It sounded to me like you only did visual, my bad

 

I could see how that's confusing.
You asked if I did a boost leak test, so I replied that I did two. You mentioned the vacuum lines, so I was saying I checked. No leaking air. In The OP I mentioned testing to 28psi, so I didn't think to reiterate. Definitely covered that base, though!

Hitting fuel cut for no reason....then running rich in open loop only..plus slow spool...
Then there is the wideband reading zero and the the timing reading crazy advanced, when the car went nuts.

I still don't know.

 

damn.. sorry no ideas here other than what's been covered.. really does sound like a leak somehow, idk. injectors? any leak there? throttle body rebuilt?

 

TB seals are about a year old. I heard nothing from the injectors.
IM going to do a third leak test with soap and water.

 

Maybe your intake pipe to the turbo is collapsing or you have some sort of restriction in your piping, like a rag left in there after doing some work.

 

FP silicone and it hasn't been near aNY rags or other debris. I would have also noticed during one of my many leaks tests. LOL

 

Have you checked the turbo/wastegate?

 

If it feels like it drastically cuts power when you hear the poping sounds, its hitting fuel cut.

If it pops and crackles and still wants to keep pulling and just feels like its cutting, it may be spark blowout, i had to gap my 2 step colder plugs down to .015" so it can ignite 46psi of boost with ethanol. Lol.

good luck buddy. You can also try indexing the plugs, making sure they all face the injector/intake manifold.

 

I've been working 12hr shifts and sick. Tomorrow is my first day to investigate and I'm already planning to do just that. LOL. Pulling the DP and also the intake, again.

Yeah, that's what I figured. It felt like popping an IC coupling.. but since they are all still on, I guess it would have had to be fuel cut. The log supports that, from what I can tell, though I'm not sure.

 

Hey man, does the car have a stock intake box? Asking because if the poppers are no longer holding the snorkel down to the rad support they lift up with rpm/speed choking airflow through the MAF. You'd see that same drop in load.

Old issue many of us found out long ago, most people have intakes of some sort so it doesn't come up much anymore

 

No, sir. Open filter.

 

OP updated.

 

Thats exactly how I thought of it when I had the vacuum hose popped off the fuel pressure regulator solenoid, +1 your probably hitting fuel cut

 

If the rag is post turbo you won't see it when doing a boost leak test. I am not saying this is your problem, but it is very similar to what I have seen before due to a rag forgotten in an intercooler pipe that made its way to the turbo. The car drives normally at low load but turns to **** at higher load/airflow.