Date:         Wed, 24 Jul 2013 09:03:32 -0700
Reply-To:     Alistair Bell <albell@SHAW.CA>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Alistair Bell <albell@SHAW.CA>
Subject:      Re: Fuel pressure regulator - acceptable pressure readings?
Comments: To: David Beierl <dbeierl@attglobal.net>
In-Reply-To:  <51eff540.c3ab340a.05fc.69f4@mx.google.com>
Content-Type: text/plain; charset=us-ascii

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
>