Lean at partial throttle?

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Hi,
why would short term fuel trims max out on both banks when only at 15 to 20% throttle but be fine at full throttle?

I can see at 18% throttle the HPFP didn't rise much (750 psi I think it was) and LPFP on 65 psi

When I went 100% throttle, the HPFP immediately jumps 2100 psi and LPFP to 76 psi. STFT were absolutely fine. Not adding or removing extra fuel.

I'm using a back end flash and E10. Hybrid turbos. Fuel scalar is at 1.15 for both banks.

Any advice on fixing via the flash?

Thanks

 

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Update: lpfp failure 24 hours later.
Guess that answers the question.

Engine died while on highway. When turning ignition on after the failure, lpfp showing only 33 psi.
Engine would die after barely starting.
After 20 min wait got it restarted. Lpfp managed to maintain 60 psi so drove home. Replacing pump next week.