Take three different gauges and you'll have three different readings.  And,
those pressure regulators are pricey, over $100 last time I checked.

Stuart

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Alistair Bell
Sent: Wednesday, July 24, 2013 9:04 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Fuel pressure regulator - acceptable pressure readings?

Well, it is a USG (US Gauge) pressure gauge. You can't be doubting those
readings can you?

:)

Yup, Bentley gives value in Bar and psi. 2.5 Bar = 36.25 psi. Leaving aside
gauge error, I was just wondering if the extra 2psi would be enough to
enrichen things beyond the O2 sensor's control ability.

cheers

ab

On 2013-07-24, at 8:39 AM, David Beierl wrote:

> At 10:47 AM 7/24/2013, Alistair Bell wrote:
>> I got a value of  (at idle, vacuum hose on/off) 32/38 psi.
>>
>> Bentley says it should be "approx. 29/36psi.
>>
>> I'm wondering if my readings are within acceptable range or are indeed
too high?
>
> I wonder how accurate your pressure gauge is.  The spec I believe is 2.5
bar, and your regulator certainly appears to be regulating.  The only way to
see how it's doing in transient response would be to use/make a differential
gauge that uses manifold pressure instead of ambient as a reference.  If you
did that it should show a basically static reading of 2.5 bar under all
engine conditions.
>
> It's a spring-loaded diaphragm blowoff valve that vents to the tank return
line.  I've never had one apart, but seems to me the spring could perhaps
get weaker but not likely to get stronger, and I don't *think* there's a lot
of opportunity for it to get sticky.  The usual failure is a leaky diaphragm
that pours gas into the manifold through the vacuum line.
>
> Yrs,
> d
>