[Billgiblet]

What is the black gadget in the center of the picture? I've been having some trouble starting, thought maybe I had a plugged fuel filter, pulled this out, and it obviously isn't a filter, or the pressure regulator, so what the heck is it? Doesn't seem like it impedes the flow at all.

Thanks,
BG

 

[carver]

Just a guess but it looks like a vacuum activated valve.

 

[Billgiblet]

No vacuum line to it, just fuel in, and fuel out. Must be stock, since it sits in a dedicated support bracket.

 

[carver]

Ok then I feel fairly certain its a fuel pressure regulator.

 

[Billgiblet]

Can't be. The regulator is located over on the passenger side fuel rail and has a vacuum line going to it.

 

[Kevin]

It's a fuel damper valve.

"The fuel pressure damper controls the pressure released to inject fuel during fuel delivery to the engine."

"The intention is to flatten (smooth out) the harmonic frequency found in the fuel lines, resulting in a more linear fuel flow."

So I guess some may call it a Pressure Regulator

 

[bman400]

Someone replaced the original fuel filter with that black object. Not sure what that black object is doing, you should replace that with a proper fuel filter.

 

[Kevin]

@bman400

No, it is meant to be there.

You can see it here in my Foz:

 

[2.5x_sleeper]

@Billgiblet your fuel filter is located in the fuel tank. Take a look at this write up in my Member Journal:

Walbro GSS342 fuel pump upgrade & fuel filter replacement

As @Kevin said, that's the "fuel damper valve". :wink:

Bobby...

['07 FSXT MODding Journal] ['03 X MODding Journal]

 

[Billgiblet]

Thanks guys! I'm going with the harmonic damper explanation, it makes sense to me. There's no vacuum hose, and the tube just goes straight through under what is probably a diaphragm that absorbs the spikes. I was just out there with an inspection mirror and flashlight and think I caught a glimpse of the actual pressure regulator under the starboard side injector rail. If so, pretty well hidden!

 

[Billgiblet]

I just managed to download a service manual and am checking out the fuel system.

The Fuel Damper Valve is shown there, but I see no pressure regulator connected to the injector rails under the hood. Maybe this explains why I can't really see it? Did they simply dispense with it on this model?

 

[Billgiblet]

Sorry, didn't realize it's an illegal down;load site. Gotta say, if that's the real Subaru shop manual, I'm not impressed. Every note seems to waste a page showing how to disconnect the battery, then they show a pretty poor illustration of the part, and basically say, take it out and put in the new one. No discussion of what it does or why it's there.

Go t it started after resetting the ECU, fuel pressure stays at about 45-50 psi according to my cheapo gauge.