narelle

my car seems to loose fuel pressure very quickly wrx ra 1993 is there a one way valve in the line or is the pressure kept up by the pump and a one way valve it doesn't hold pressure to the fpr so am wondering if it is flowing back as I have pressure at the filter taking the out pipe off but when I take the supply pipe to the fpr regulator there is hardly any fuel getting to it wondering if this could be injector o rings or pump letting it flow back cheers