phunk

that is an example of a unhealthy fuel pressure curve. a side effect of upsetting the balance in the fuel pump module by putting a larger pump in without making the proper modifications to accommodate the much higher bypass fuel volume.

your fuel pump is overwhelming the regulator and/or venturi passages behind it. i am guessing you have larger than a 255lph in there to see as high as 72. the canister fill venturi on the bottom of the fuel pump module can be opened up a bit to bring your pressure back down. (this can serve as a reminder to me to work more on my (not-yet-so) "ultimate fuel pump" thread.

the pressure comes down when you start burning more of the fuel because there is less volume that the regulator has to relieve, and backed up pressure from the venturi blockages begins to lower

so the issues are correctable. if your A/Fs are staying inline, there is no immediate rush to resolve it.

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