Thread: Fuel Pressure Prime Question

Clamp the white line.

Personally I would switch to a Nismo FPR but that's just me.

Confirmed, i clamped the white line and the pressure stops dropping....that mean the check valve on the fuel pump is no good? [Walboro]

From my research, if it stopped falling when I pinched the feed line it would be the check valve on the pump tho right? So should I be looking at the FPR as the issue?

Replace the FPR.

Ok thanks bud ill try that and report. I was thinking maybe like a Nismo FPR (if i can find one at a price a workable price) and throw an pressure gauge inline the feed hose...like from the fuel filter to the rail so i know my pressure?


Or perhaps go this route and just pull the gauge off my current one to put on this one?
http://www.ebay.com/itm/New-Aeromotive-13129-EFI-Fuel-Pressure-Bypass-Regulator-/251284985342?pt=Motors_Car_Truck_Parts_Accessories&hash=item3a81c095fe&vxp=mtr

I'd pass on that on personally. Nismo P/N is 22670-RR580-US. I just found a new one in the box under my TV last week. Go figure.

So for some reason today when I started it and prime the damn hose kept blowing. It was prob pretty old so I got some fresh fuel injector line and put it on, solved the issue. Picture below of where it kept blowing out.


Since i just got my wideband installed a few days ago i took a quick video of the numbers running. Dont mind the screen, I havent gotten around to mounting it yet lol. Video is footage of the AFR, RPMs, AFR, then to engine bay to see the FPR gauge, then just some footage of engine, then back to the muffler to give that a listen, then underneath to hear the fuel pump, then back to the AFR before I shut the car off. Looks like its running up around 20 in bitch lean terriority, so would that condition support an issue with the FPR?

Here's another video of me pulling the vac line off the FPR to make sure its adjusted ok. Looks like around 44ish psi vac off and drops to about 38ish psi vac back on. Dunno if you can tell but engine sounds weaker like it might die when i have the vac off, didnt keep it off long enough to find out though. In the few minutes i ran it i didnt see any fuel coming out of the vac hole either.

That is the proper fuel pressure for Idle.

Does the fact it doesnt hold pressure in the line a problem only for start up since it holds proper pressure while its running? I'll still prob swap in a known working FPR to see if that solves the holding pressure issue, then imma blow some smoke thru a vac line to see if it leaks out anywhere to make sure i dont have some little vac leak somewhere...beyond that i'm not sure what else to do. I'm hoping perhaps its some small vac leak somewhere though

It wont affect drive-ability, and likely will not cause much starting issues. Just let the fuel pump run for a few seconds before you start the engine.