Soft limp mode when at WOT 1.8t

[devbloggs]

Hello everyone,

i'm looking for some suggestions / help with an issue i have with my 1.8t

Issue :

At WOT the car will start to build boost and take off as it should, but at about 4000 RPM, the boost dies off and i get the 5 psi soft limp until i let off the throttle completely and lean into it again.

The car will build up to the 20 Psi it's supposed when the car is driven down a somewhat steep hill but that's the only time it will reach 20 psi.

the car idles fine and other then a lack of boost under load, it drives normal and i have yet to hear a misfire.

the other thing Ive noticed is if I'm at WOT and let the gas pedal off right when it usually drops to 5 psi, i get the fluttering sound from the diverter valve

Parts Replaced \ Upgraded :

Forge splitter valve
brand new OEM MAP sensor
2 New coolant sensors
Newer spark plugs (gapped to .028)
new air filter / oil change
Unitronics Stage 1+

Steps Tried :

Visual check for boost leaks
Visual inspection of wiring harness / connectors
cleaned SMIC of oil
Tried unplugging MAF, no change
Checked for Codes ( NONE :S )
Fixed exhaust leak after CAT
Cleaned throttlebody

any help would be appreciated, I have VAG-Com and have some knowledge on how to use it.

[Ricas]

Sounds like a dying ignition coil.

[devbloggs]

any.way to.determine which one?

[devbloggs]

bump

so i acquired a known working n75 valve and that didn't fix the issue. I also bypassed the n249 valve and that hasn't fixed the issue either. I installed a mechanical boost gauge and it seems like the boost dies at about 19 psi until I lift off the throttle and re apply the gas

[ipop07]

vag com and figure out if you have misfires..

[BellCityDubber]

Hello everyone,
I have VAG-Com and have some knowledge on how to use it.

Do you?
why didn't you post a CEL scan?
You "cleaned" the throttlebody, but have you done an adpatation thru vag-com?
Have you went logging thru measuring blocks to reproduce the conditions?

I'm surprized nobody asked these questions earlier...