fuel pressure dropping over time

RustyRatRod said

I know, I'm just sayin the factories used that .060" "or whatever it was" orifice in those return filters, so they musta thought it was enough. I have a WIX return filter with the orificed return. I should go see how big it is.....or how "small". lol

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They also do things like pulse width modulation on the electric fuel pumps. Which makes the fixed orifice return much less of a restriction. If you can reduce pump output when the engine doesn’t need it everything works better. Less heat in the pump and the fuel and a lot less return. The big manufacturers do a lot of testing and have narrowed it down pretty well.