Confused about the fpr

[eclipse787]

What exactly is the fpr regulating the pressure coming from the fuel pump going into the fuel rail, or to keep the pressure high and regulate from the fuel rail back to the tank?

[kjewer1]

The FPR regulates pressure at the regulator and back toward the pump. In other words, everything from the pump outlet to the FPR is pressurized. From the FPR outlet, excess fuel (fuel pumped up to the rail but not consumed or required to maintain pressure) is sent back to the tank at low pressure. We only care about fuel pressure in the rail/at the injector and that is what is regulated. Hope that clears it up.

[eclipse787]

thanks that makes sense now. so then how much pressure can the seals on a 95 fuel rail handle? if im running no more then 7 lbs of boost about what pressure should i have it set at?

[david-b]

Originally Posted by eclipse787

thanks that makes sense now. so then how much pressure can the seals on a 95 fuel rail handle? if im running no more then 7 lbs of boost about what pressure should i have it set at?

Turbo or non-turbo stock model?

Stock fuel rails will hold up to ALOT of pressure. That's what they're built for.

On my car (95 ESi n/t converted to turbo), I run 7psi also. I have a 12:1 FMU controlling the pressure. Idle, fuel sits at ~40psi. When I hit boost, for every 1 psi I get, the FP goes up 12psi. So "what pressure" should you have it set at, doesn't really make sense unless you're talking base idle FP.