Risking a lean condition on our engine's is a big no no. Do you have an EGT gauge? I used to notice lean conditions a lot easier with my EGT than I do with my old narrowband A/F gauge (get a wideband 02 sensor like the one from zeitronix). I originally tested my fuel pressure with a fuel pressure gauge screwed into the test port on the fuel rail(can rent them for free from Autozone and other similar stores). Just prop the gauges under the passenger windshield wiper so you can read it while driving and take a roll of electrical tape (or somthing similar in thickness) and lay it flat near the hose on the wiper sill. That way when you shut the hood it doesn't pinch the hose. 5-7 psi should be roughly in the 85-90 psi range I believe.

Jamie-
-AUTOMATIC turbo'd 95 Talon ESI@8psi (stock internals)14.0sec=1/4 mile

-2003 Mitsubishi Evo VIII