Fuel Pressure Gauge Positioning

[240sxed]

I bought these two items Plus the nismo FPR.

B&M Fuel Pressure Gaugehttp://store.summitracing.com/...earch

Summit racing 3/8th fitting so I can splice into the fuel lines

http://store.summitracing.com/...earch

I scrwed the fuel pressure gauge into the "T" fitting and then T'd it into my fuel return line. It reads about 19 psi... and flickers 18-19. I T'd it after the fuel pressure regulator and before the hardline going down under the chasis. I know that can't be right....or that Im putting it in the wrong place? Am i suposed to place it on the inline between the fuel filter and fuel rail? I figured I'd only do the gauge first , get that right and then do the fuel pressure regulator.

btw, walbro 255 on rb25det in s14.

[Bluefire]

Position is wrong, gauge needs to be before the pressure regulator to read the correct pressure. Also How are you using a 3/8 adapter when the fuel lines are supposed to be 5/16th?

-Bluefire

[240sxed]

Mmm... I guess the fuel lines fit, Maybe im using a 3/8th fuel line? I don't remeber what size it says on the lines...Would that make a diff in pressure?

Position is wrong, gauge needs to be before the pressure regulator to read the correct pressure. Also How are you using a 3/8 adapter when the fuel lines are supposed to be 5/16th?

-Bluefire

[Joe]

your missing the point

the gauge is in the ENTIRLEY wrong position. it needs to go before the pressure regulator. since you are after it you are only reading the pressure of the fuel on the way back to the tank. not the pressure the injectors get.

it goes between the filter and fuel rail.

[Bluefire]

Mmm... I guess the fuel lines fit, Maybe im using a 3/8th fuel line? I don't remeber what size it says on the lines...Would that make a diff in pressure?

No the fuel line size has nothing to do with the pressure. Like I already said, your gauge is in the wrong spot. I'm just saying that you should be using 5/16 fuel line. Your gonna have to keep an eye on the 3/8 line from leaking

-BLuefire

[240sxed]

I know the position is wrong, just wondering if I was using the wrong size, would it ALSO effect it even if I had it in the right position. But yeah thanks for clarification.

[gawdzilla]

can anyone give a final confirmation on the size? i'm about to buy my FP gauge. 3/8" or 5/16"?

both the KA (body) and RB (motor) feeds/returns are 5/16"?

[240sxed]

pretty sure its 5/16" I bought a b&M one so its domestic sizes....

Anyhow My gauge reads 40 with vac line, and 49 with vac line on fpr. btw using stock fpr, tommorow I'll probably switch it to the nismo unit.

[jdmser]

5/16 is 7.9mm our fuel line is 8mm so its a good fit. 5/16 hose will also slip over the end of a 6an socketless fitting(hose barb) with a little lub and some effort

[Ramius83]

GAWDZILLA: 5/16" fuel line is as close to stock as we can get here in the states. That is what I have been using on my Nissans for the past 5 years.

As jdmser said, it has an inner diameter of 7.9x mm, and Nissan OEM line in Japan is 8mm.

[Dano]

Our own SPL Parts sells an 8mm hose 1/8 BSPT adapter for $12

-Dan