Do you normally start the van by turning the key to *ON* ( not start )..
then listen for the fuel pump to run, aand then shut off...before
turning key to 'start'  ??

I ALWAYS do ...warm or cold.
it's fun.
it's never actually correct to turn the key straight to 'start' ..
one is suppossed to confirm warning lights are working ( during which
time the fuel pump pre-runs ) *before* turning the key to start.
see Owner's Manual.

I think you are chasing a mostly non-problem.

There isn't something that needs rust restoration or treatment on your
van ?

On 3/3/2014 5:49 PM, Neil N wrote:
> So I'm running residual pressure tests with a fuel gauge installed.
>
> The system holds pressure for 10 minutes then very slowly drops. After
> about 45 minutes, at 20 PSI, I bled off pressure at gauge. Using FP
> relay bypass switch, if I turn the fuel pump on for 2 - 3 seconds then
> off, system pressurizes to ~ 40 PSI but then pressure rapidly drops to
> 0 in less than 5 seconds. Clamping supply hose stems this pressure
> loss. I assume this is being caused by the check valve in the pump
>
> I doubt it but.... does the check valve in the Vanagon Bosch fuel pump
> require pressure to be maintained for a certain period of time before
> the check valve is actuated? And, if the pressure drops too far for
> engine to start easily, and the pump (normally) only primes for one
> second, in my case, it seems the check valve isn't able to keep
> pressure.
>
>
>
> On 3/2/14, Neil N <musomuso@gmail.com> wrote:
>> Right, ok. I should mention now that this is in regards to a Jetta 2.0
>> in my Vanagon. A3 Bentley says to clamp the fuel return hose. If
>> pressure holds, regulator is at fault. If pressure drops, pump check
>> valve at fault.
>
> --
> Neil n
>
> Blog: tubaneil.blogspot.ca
>
> '88 Westy http://tinyurl.com/c8rlw6p
>
> '81 VanaJetta 2.0 "Jaco"  http://tubaneil.googlepages.com/
>
> Vanagon VAG *Gas* inline-VR Engine Swap Group:
>
> http://tinyurl.com/d7gd5ej
>