In some cases, the fuel pump not delivering enough volume could explain what you're describing. However, I don't think that's the case for you at only 10 psi. If it was 20, than maybe.
You should verify that you are actually loosing fuel pressure. Tape a pressure gauge to the wiper blade and go for a drive.
My car would keep reading lean and I couldn't figure out why. Ended up being a faulty 02 sensor. You can try this test:
https://www.youtube.com/watch?v=onbjzEOZtMs