fuel pressure

[rhtuners]

I would not be posting this if i don't already search no one has the same problem as me. This is my problem installed Sr20/370cc injectors aftermartket FPR. Now when i turn my key to the on position the FPR reads 20-psi and then it drops to 0-psi. If i start my car all the way it idles at 20-psi for fuel pressure but when i try to drive it starts bucking and then shuts off, to keep it running i have to keep giving it gas. I am thinking that my stock fuel pump is not working and that i need to upgrade to a walbro 255 pump what do you guys think?
Setup
t/3-t/4 turbo
e60 maf
sr20- 370cc injectors
stock fuel pump
aftermarket FPR
vacuum block
ssqv BOV
stock block ka24de

[UNISA JECS]

Yea that fuel pump is toast if your only getting 20psi with key in the on posistion, engine off, you should be able to get 43psi with key on engine off for a brief period.

[rhtuners]

o.k. so i just picked up a walbro 255 fuel pump i hope this will fix the problem then will install it tonight

[rhtuners]

also is it normal for the stock pump to work fine before the turbo install and not work after i install everything that is strang to me but then again this is my first build

[UNISA JECS]

Just coincidence, I ran my stock pump for a while before I upgraded.

[!Zar!]

You should always upgrade your fuel pump when going turbo.

Probably just overworked yours and it's dead.

Try unplugging your maf and see if that makes a change.

[dorkidori_s13]

uh...honestly...what kind of FPR are you running...if its ANYTHING but a aeromotive or more expensive SARD...its more than likely the cause of your problems

cheap FPRs tend to take a shit very quickly as the internals on them are total CRAP (i sent 160 bux on a stupid NISMO adjustable FPR...wow that thing was a total waste of money...it died on me after about 3 months of use...went to a aeromotive -6an fitting FPR with JEGS CF liquid gauge...never looked back...been in my car for almost a year and a half now...works like the day i got it)

your stock fuel pump SHOULD handle about stock SR horsepower fine...wont be the best pump in the world...but for a OEM pump to take a shit isnt very common

be careful with your walbro...DO NOT RUN YOUR CAR UNDER 1/4 OF A TANK!!! YOU WILL RUIN THE PUMP LIKE THAT!!!...ive been thru 4 walbro pumps (wont ever touch em again)...but after MUCH research about why they kept dying on me...come to find out that if you run walbros under 1/4 of a tank of gas you are actually causing a good deal of damage to the pump itself just because of the heat it produces...basically it eats itself

also...when you wire up the walbro...wire in a resistor so you can run a straight 12 volt line from your battery to your sending unit...i dont care what ANYONE on this forum says...ANYTIME you upgrade your fuel pump past OEM...you are not supplying correct voltage to it...the OEM wiring is CRAP on S13s and S14s...u drop about 2-5 volts when wiring up an aftermarket pump...which WILL cause fuel problems...like i said...run a resistor back near your pump (adding a fuse in the line is a good idea too) and make sure the pump receives a full 12 volt charge otherwise it wont run properly

[jspaeth]

Yep....with stock fuel rail, if you get less than the right fp, your fuel pump can't keep up with the injector demands or whatever.

Bigger than needed fuel pump = okay

.........bc all that matters is the pressure in the fuel rail, which is regulated by the FPR......the excess goes back to the tank


Underpowered fuel pump = can't provide the needed FP at the rail