Loss Of All Power At First Sign Of Boost

[Alex2016]

Thanks in advance for any help,

Ill try to lay out the problem and be as specific as possible:

Truck is 2016, only 32,000miles. G56.

Issue: Truck falls on its face immediately after the first sign of boost. Typically the engine does not die. I can not get going very fast. 1st 2nd gear I can idle around in or very low throttle, as soon as I see about 1psi boost or hear any turbo it looses all power. If I do not press the clutch in it will; have power-loose power-have power-loose power and buck the truck around like crazy (due to being in first or second gear) as if I’m pressing the throttle on off on off. If I do press the clutch in right away it just goes to idle and I can try again.

The truck has only died once at idle. There are no codes or CEL. The truck does not smoke or sound abnormal. It starts fine. All gauges look normal (fuel pressure is normal) I can also rev to any RPM in neutral fast or slow without issue.

History: Truck has been deleted since brand new off the lot (deleted 200 miles in). I have been running the raceme ultra box tune until recently.
Recently I installed compound turbos Fleece cheetah/S475 with pushers kit, studs, injectors, bag of parts etc...I drove for a week on the box tune with no issues. I have since had custom warp-tuning and the truck drove amazingly for the last week without issue. Probably put 500-800 miles on it. Mix of light towing, highway and city traffic.

There was no build up to the issue. Drove fine yesterday all day, this morning didn’t make it off my street.

What I’ve checked:

No boost leaks
MAP & MAF plugged in
No visible cut, melted, frayed, pinched wires
Batteries are fairly new and good
re tuned to box tune-no change
re flashed custom tune- no change
zero mechanical issue as far as sound, smell, and looks go
no change weather engine is hot or cold

Im at a loss as to where to check next, other then blindly replacing sensors.

Long post, but thanks for taking the time to read.

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[DDP]

If you don't mind me asking how did you go about testing for boost leaks?

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[Alex2016]

I stuck a pvc plumbing cap in the coupler going into the atmospheric turbo with an air chuck on it. Barred the engine over until I stopped hearing air go into the cyl and applied 40PSI. I listened for air—heard no apparent leaks. And sprayed soapy water on all couplers and intake gaskets and did not see any bubbles.

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[DDP]

I stuck a pvc plumbing cap in the coupler going into the atmospheric turbo with an air chuck on it. Barred the engine over until I stopped hearing air go into the cyl and applied 40PSI. I listened for air—heard no apparent leaks. And sprayed soapy water on all couplers and intake gaskets and did not see any bubbles.

Hmmm check the intercooler boots as well if you did not. Might see if there is an update or something that needs to be done via the tuning. How this would affect your issue i have no idea but stranger things have happened. Who did your tuning? Might see if you can get a log going to help you pinpoint the issue if there is one to find utilizing the log.

Hopefully it's something silly like a sensor and nothing more. Still you would think there would be some type of code.....

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[Alex2016]

Hmmm check the intercooler boots as well if you did not. Might see if there is an update or something that needs to be done via the tuning. How this would affect your issue i have no idea but stranger things have happened. Who did your tuning? Might see if you can get a log going to help you pinpoint the issue if there is one to find utilizing the log.

Hopefully it's something silly like a sensor and nothing more. Still you would think there would be some type of code.....

I checked all of the boots, intake from filter to grid heater was pressure tested.

Yeah Im hoping it’s a sensor. Aside from MAP and MAF. what other sensors could cause this. I’d assume the Crank position sensor if bad would exhibit issues in neutral not only under load?

Today I will pull the MAF sensor right out, leaving it plugged in and see if it makes a difference. Sensor looks clean tho. No oil or dust/dirt on it.

My tunes are from Ray at DRD. He has been very helpful as I asked him a few questions, and got back to me right away. I’m trying not to go down the data log route until I cover all the usual suspects/easy stuff.

It will also also be hard to log as it’s is virtually un-drivable in this state.

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[RamIt]

Are you absolutely sure you don't have codes? Have you checked pending DTCs?

A sensor failure (MAF/MAP) should be throwing a code. Hell, a sensor out of range will throw a code.
Who did your tuning?

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[Alex2016]

Are you absolutely sure you don't have codes? Have you checked pending DTCs?

A sensor failure (MAF/MAP) should be throwing a code. Hell, a sensor out of range will throw a code.
Who did your tuning?

I have scanned with my banks idash 1.8 as well as an autel scanner. Nothing is showing up in pending or active codes. This is bizarre to me as well

DRD provided the tuning. Everything worked fine for the first week of driving. I exposed it to all types of driving conditions too

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[RamIt]

I have scanned with my banks idash 1.8 as well as an autel scanner. Nothing is showing up in pending or active codes. This is bizarre to me as well

DRD provided the tuning. Everything worked fine for the first week of driving. I exposed it to all types of driving conditions too

Interesting.

Next question, are you running a factory MAP?

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[Alex2016]

Yes all of my sensors are the factory OEM sensors.

Only aftermarket sensors I have are connected directly to my idash module and have zero integration with the ECM

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[RamIt]

Yes all of my sensors are the factory OEM sensors.

Only aftermarket sensors I have are connected directly to my idash module and have zero integration with the ECM

You might want to look at getting a 10 Bar MAP. I'm wondering if your compound setup is maxing your MAP out. Cause if you have no codes, no air leaks, and no fuel issues; then the problem lies somewhere in the information your truck is trying to operate off of.

Can you run a datalog with your Ultra & make sure you include Rail pressure, RPM, Boost, & MAP voltage? Should be able to narrow down if your MAP is out of range pretty quickly.

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