Fuel Pressure issue.

[Steve Powell]

I run 90's Ford EFI stuff. When I "charge" the fuel rail by energizing the fuel pump (turn the ignition on) the pressure rises to the requisite 39 psi as it should but it will drop back to zero very quickly. When I say quickly, like a second or two. It should hold pressure for several minutes. Does this mean my pressure regulator is bad and "leaking" fuel back to the tank via the return line? Does the regulator act as a check valve? The regulator is an aftermarket Aeromotive adjustable unit. I have a stock unit I could put on as a test but would prefer not to if someone knows the answer. The other option is I have an injector stuck open. I don't think so but it is a possibility.
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Street car...FFR 3904K 347 EFI, T5, 8.8 3 link, 15" Team III's.
Track car....FFR 4662SP 302 EFI, T5, 8.8, 3 link, 17" Toyo's

Fits like socks on a rooster.

Steve

[karlos]

I believe that's normal for an Aeromotive EFI regulator. See item #6 here:

https://www.aeromotiveinc.com/tech-help/faqs/faq-efi-regulators/

[Steve Powell]

Karlos, thanks for the info. It does seem that the pressure used to hold. Maybe the seal is getting worn a bit. I also checked other cars and they do hold pressure for a while but they have different manufacturers of regulators so that's probably not a good measure.