Rico, I just replaced my regulator, = but it had the opposite problem of yours. It was stopped up tight.  I didn't = realize what was causing my super-rich running problem (1/2 tank of fuel in the = final 43 miles, after which it wouldn't even run.) until I put a gauge on it and = realized I was running 90-plus psi fuel pressure!  Yikes!  Glad I had = replaced the fuel lines recently... It's supposed to be more like 30 or so.  = Anyway, fresh regulator fixed me right up.
 
Being the curious sort, I used a hacksaw and cut the = old one open.  (Don't try this unless you first let it dry out more than I did...)  Mine was full of scale and rust, but I could see it's = function and can confirm for you that it is NOT supposed to let fuel through, in = either direction, when the motor isn't running.  If you're siphoning fuel = through it via the return line, it's definitely not working = properly.
 
Like Ken said, it holds the pressure in the system = for a long time after you stop, but also stays shut when you first start, allowing = the pressure to build more quickly.  This aspect of it also cured a = hard starting problem I'd had for 3 years, that I had assumed was just low compression.  The motor used to turn over about 4 times before = starting, now it starts instantly.
 
BTW, my "test gauge rig" was two used hose = clamps, a piece of leftover fuel line, a $1.28 hose barb and a $4 water pressure = gauge from Lowes.  Wish I'da made it up a long time ago....
 
Carl
82 Vangon L, = 83 GTI, 86 Scirocco
+  +  +  +  = +  +  +  +  +  +  +  +  +  +  +  = + ++
Date:    Fri, 25 Feb 2000 19:50:16 EST
From:    kenneth d lewis <kdlewis@JUNO.COM>
Subject: = Re: Fuel pressure = regulator

Rico;
        I can not speculate from those symptoms. Your best bet is to put
a = gauge on it.
        I permanently = connected a gauge using parts I had laying around
the garage. I left the gauge in = the engine compartment. My system holds
pressure for more than an hour = after being turned off.

Drive Safely & Good Luck
Ken Lewis    <Kernersville,NC>
86 VW crewcab;60 356B = Coupe
+  +  +  +  = +  +  +  +  +  +  +  +  +  +  +  = + ++
Date:    Fri, 25 Feb 2000 17:22:18 EST
From:    Rico Dagastino <Dagbear@AOL.COM>
Subject: Fuel = pressure regulator

  I disconnected from the fuel filter (the large = metal filter between the
pump and the injectors) the hose which connects = the filter to the fuel pump
in order to test the fuel delivery rate of the fuel pump.  I found that rate
to be quite adequate.  While = conducting this test I was forced to plug the
open end of the hose coming from = the injectors because fuel was siphoning
through the system.  My = question: Would a properly functioning fuel pressure
regulator allow the = reverse flow of fuel through the system at a rate to
sufficient to cause this = siphoning action?  If not, can this be construed as
a sign of a defective = fuel pressure regulator?  I know this reversed flow was
not caused by = accumulated pressure in the tank because I removed the gas cap
so as = to allow any pressure to vent.  Would it now be appropriate to test = the
operation of the regulator by applying a test gauge to the line?  I = am
searching for the cause of an intermittent dying condition not caused = by
electrical malfunction.  Any help would be greatly appreciated.

Rico Dagastino
Munford, TN
84 GL "Thing 1"
87 GL = "Thing 2"