I am installing a mechanical fuel pressure gauge on my fuel line but i was wondering if it should be installed before the FPR or after it??? I noticed the fuel pressure valve is on the fuel rail and thats how i tested my line pressure (thats after the FPR) Would i get the same reading if i installed a gauge before the FPR???

 

the source for the gauge can be tapped at any point along either fuel rail. As long as the source for your readings is at the same pressure as your fuel injectors are getting, then it'll be accurate... so pretty much anywhere along the feed side, and not the return line.

 

ok so let me get this right. fuel line feed runs from pump to fuel pressure regulator then runs through the fuel rail, then to the injectors. So what you are saying is that the pressure in the line BEFORE the fuel pressure regualtor is the same as the pressure in the rail (thats after the regulator)??? get back to me.

 

i was just checking to see if anyone replied but not yet. you said u need to tap in at either fuel rail. I just got done installing a gauge on the line that runs next to the battery. I get a reading of 38psi idle and when i rev it shoots to 43psi. Can i adjust the fuel pressure on my regualtor watching this gauge or do i always have to use the fuel rail shrader valve???

 

Sounds like you have the correct line. The pressure drops at idle because of engine vacuum pulling on the pr diapram.Most of the permanent guages ive seen connect rigt to the schrader valve by removing the internal check assembly.

 

Mine is connected in-line on the upper rubber fuel hose right by the washer fluid tank. I connected a fuel pressure gauge to the schrader valve and compared it to one on the fuel hose and they're identical even when I adjust the fuel pressure. It's located on the bottom right hand corner right under the Ultra Coil.

 

thanks pwdbychevy - thats exactly what i needed to know. Installed and lookign good. now for tuning soon

 

No problem dude