So to day i decided to finally put in my walbro fuel pump, did it got er running, then i installed my Fuel pressure gauge (Inline after the filter and before the fuel rail) and i was told that it should stay pressured by turning the key over and letting the pump turn on, But as soon as the pump shuts off the fuel pressure drops emediatly... What could be the prob. this is with my vacume hose plugged in.

Fuel pressure reads(with car on and vacume hose on) Right under 3 bar

when i shut the car off, it drops to 1 bar of pressure...

im trying to get this figured out before install my Nismo FPR...

TIA

if im not mistaken the regulator goes after the fuel rail before its starts to go back to the fuel tank. check that out.

you mean the fuel gauge? I havnt installed the FPR yet, i just installed the Fuel pressure gauge it does nothing but tell the fuel pressure.

yes sorry read your wrong. but it should drop as soon as you turn of the car because the fuel pump is not pumping. it some thing normal, whats your prob or question

i read on another thread that the fuel pressure stays the same afterthe pump is turned off.

Here is a link to that thread

http://sr20forum.com/showthread.php?t=153743&highlight=FPR+install

the preasure will go down , but for some cars may take a lil longer but it will go down, but if your car is not giving you trouble leave it like that

the preasure will go down , but for some cars may take a lil longer but it will go down, but if your car is not giving you trouble leave it like that

agreed. My fuel pressure gauge goes down after turning off the ignition. just make sure the fp maintains 3 bar at idle.

right, you look at pressure while the pump is on. Once it kicks off it will slowly go back down as there are pressure vents on the tank and so on. I think you are fine there, now move along to the FPR!

Brent

Sorry for the threadjack, but how long does it take the FP to go down in your guys' case? Mine creeps down VERY slowly, to the point that it'll take a couple of days of sitting to reach 0psi. This is on a 4 bar setup.

there should be a check valve in the in-tank pump that maintains pressure in the lines after shut off. If your pressure drops imediatly you may have problems with hard starts due to the vapor that is created in rail when you shut off a hot engine.
-dave

I am also running a 4 bar setup on my regulator and my pressure drops to about 2.5 bar when i switch the ignition of , it will stay there for about an hour and slowly drop down to 0 bar overnight, i cannot see how the pressure should stay up since there is nothing to pumping through the regulator .

if im not mistaken the regulator goes after the fuel rail before its starts to go back to the fuel tank. check that out.

The fuel gauge goes on the return line??

like dave mentioned, the fuel pressure should drop VERY slowly after shutting off the car. If it drops immediately, there's a problem.

The fuel gauge goes on the return line??

Fuel pressure gauge on the feed line, FPR on the return line.

Oh ok, i was getting really confused. I just got the nismo one that hooks up into my fuel rail, only one way to put it in.

actually, you can put it in however you want. If you want the fuel return hose to be shorter, then point the outlet towards the driver's side. If you want easier (IMO) access to the adjustment knob, face the outlet towards the passenger's side

Fuel pressure gauge on the feed line, FPR on the return line.

the Nismo fpr bolts right into the stock rails at the feed line. every fpr setup i've seen is on the feed line only, gauge and fpr.

^^^ huh?
the frp is on the return side of the rail after the injectors thus keeping + pressure for the injectors.

put the nismo fpr on man I have the same setup walboro gauge and nismo fpr it will drop slow after the install.

^^^ huh?

fuel filter ---> pressure gauge ---> Nismo fpr ---> fuel rail ---> out the return line.

if you can find a pic on line of an SR20 engine setup differently i would like to see how its done.

fuel filter ---> pressure gauge ---> Nismo fpr ---> fuel rail ---> out the return line.

if you can find a pic on line of an SR20 engine setup differently i would like to see how its done.
this is the proper set up
fuel filter>>preasure gauge>>FUEL RAIL>>nismo FPR>> return line>>gas tank