sounds like you are having a residual pressure issue due to a failing fuel
pressure regulator.

The one-way valve in fuel pump and the fuel regulator itself, maintain
residual pressure in high pressure side of fuel system, once engine is shut
off. I don't recall the Bentley spec but my Digifant pro manual (found it
on the 'net) says residual pressure should hold for 10 minutes.

Another possible cause of poor residual pressure is a leaking injector(s)
but given the lower fluctuating fuel pressure you see, that likely isn't
the issue.

Neil.

On Thu, Oct 31, 2013 at 7:22 AM, Max Wellhouse <dimwittedmoose@cfu.net>wrote:

> .1990 GL  2.1 with 260k + (120k on a boston bob overhaul)
>
>  I've been keeping a fuel pressure gauge signal going to my VDO oil
> pressure gauge(toggle switch to change sources) and for several years it
> read right between 29-36psi  just like it should.  Then about a year ago
> it dropped down to fluctuating to a reading like 17-20 psi.  The engine
> still started and ran okay, but within the last couple of weeks, i've
> run the gas tank past empty on two different occasions and had to
> reprime the fuel lines and bleed the air out of the lines from the test
> port screw.  That seems to be the onlywlay to restart a totally dry fuel
> system.  The second time it ran dry, repeated attempts to bleed the air
> etc. have proven to be unsuccessful i ngetting it to start again
>
> ....
>

> Could the fuel pressure regulater be causing these issues of no pressure
> at all?

--
Neil n

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