2004 stock B6 1.8T: fuel pressure - injector duty cycle

[vtraudt]

Fighting very odd behavior on this car. Had throttle cut, timing pull, all sorts.
Found china turbo with flapper not opening. Stock actuator and some grinding eliminated the throttle cut.
Boost control is now decent at 7.5 psi, slight taper down7.0. N75 at 30% (seems low for K03 turbo).
Injector duty cycle going to 90% (seems high for stock tune).
Actual AFR is slightly lower than desired, but follows. At 5k rpm drop 13+ to under 12 (enrichment).

Still up to 12 degrees timing pull on all 4 cylinders.

Car got new fuel pump and filter, MAF.
N75 swapped as part of troubleshooting.
Forge DV.

Fuel pressure:
56 psi at idle
58 psi under part throttle vacuum
52 psi under WOT boost (as low as 50 psi).
Is this normal?
B6 has fuel pressure regulator in fuel filter, and NOT a raising rate (like other 1.8T and 2.7T).


Any suggestions?

[blitz2190]

at 90% it seems like its looking for fuel, has the filter ever been replaced, filter could be clogged or fpr may be going bad, rare but can happen.

[vtraudt]

at 90% it seems like its looking for fuel, has the filter ever been replaced, filter could be clogged or fpr may be going bad, rare but can happen.

New filter AND new pump (done by shop the car had been at prior).

[blitz2190]

does it smell like it running rich even though it says lean? My thought being you may have the front wideband giving a bad reading, just a thought, if you have a spare to try.