Date: Sun, 20 May 2012 19:50:30 -0700
Reply-To: neil n <musomuso@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: neil n <musomuso@GMAIL.COM>
Subject: Re: Use Air Cooled Fuel Pressure Regulator on WBX?
In-Reply-To: <BAY152-ds15ED66F3C7C40AB3637BC7A01D0@phx.gbl>
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The FPR had surface rust. It is a little pitted as a result.
image: (hope this works. am posting via my old iMac OS 9 here in the basement)
https://lh5.googleusercontent.com/-qNR3z6hf-bM/T7LNaa6Z3LI/AAAAAAAAFxg/cqN_uhf1lYs/s340/FPR%2BRust.jpg
I've seen first hand the results of a failed FPR diaphram. The PO
thought the engine had seized (lack of oil or whatever). Well it was
seized in a sense; hydro locked. Crank case was FULL of Goil! (gas +
oil. My term © ;^) Saved that 1.9 and it went to someone who
needed it.
The work history on my new bus (shameless posting of image:
https://lh4.googleusercontent.com/-vC9JsVen6kU/T6HpOIzyjEI/AAAAAAAAFp0/_h3NK77vaLw/s340/New%2B88%2BWesty%2B3.jpg
is sparse. Work has been done but haven't dug in to see what is what.
As for the FPR, I am likely being type A cautious but so be it. :^)
Neil.
On 5/20/12, Dennis Haynes <d23haynes57@hotmail.com> wrote:
> Why do you think you may need to replace the fuel pressure regulator? They
> are easily tested and almost always a failure is obvious. The typical
> failure is the diaphragm which becomes obvious as the intake manifold gets
> filled with fuel or the shell gets rusted it leaks on the outside. If it is
> a case of low fuel pressure the regulator can be tested by crimping the
> return hose. If this raises the pressure to the required pressure then the
> regulator is leaking by.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
> neil n
> Sent: Sunday, May 20, 2012 11:31 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: Use Air Cooled Fuel Pressure Regulator on WBX?
>
> Cool. Thanks David.
>
> My gut told me that there might be some issue with both return lines
> pushing
> fuel into one inlet. But as you suggest, I could measure pressure.
> Thanks for explaining.
>
> A brass " T " isn't available at my FLAPS, but it does exist of course and
> is what I would've used.
>
> The FPR bracket is easy to bend but maybe only to 45º maximum. Hose routing
> to accommodate the single inlet type FPR might be difficult. e.g. I found
> that even "just" moving fuel rail hoses to top of intake, and feed/return
> hoses over to driver side of firewall presents a challenge. (where will it
> chaff, wires nearby etc.) A single inlet FPR, with FPR bracket bent to
> max.,
> at best, (in my minds eye) would still put the return hoses at an awkward
> angle. The feed hoses to new " T " would need to be curved thus routing
> them
> over parts.
>
> So theoretically possible but hose routing might make the idea moot? I
> don't feel like spending more money on a test part but could mock something
> up I guess.
>
> Neil.
>
> On Sun, May 20, 2012 at 12:26 AM, David Beierl
> <dbeierl@attglobal.net>wrote:
>
>> At 02:10 AM 5/20/2012, neil n wrote:
>>
>>> A " T " would be required at inlet, there would be 2 more hose clamps
>>> than with the WBX part, positioning it might be a problem, but other
>>> than that, will the part work correctly?
>>>
>>
>> I haven't done it, Neil, but I don't see any likely issues. The AFC
>> fuel pump delivery rate is the same, injection pressures same, the
>> venting rate back to the tank should be the same or less. The AFC
>> system appears to feed at one end of the system and vent at the other;
>> the later ones feed at both ends and vent in the middle (or to say
>> another way, feed the two sides of the engine in parallel) which gives
>> both sides the same inlet fuel temperature. Doing it that way it
>> becomes more convenient to have two input nipples on the regulator.
>> The only possible (not likely) issue I see with using a tee is
>> turbulence/noise/restriction where the two flows are constricted,
>> meet, and abruptly turn 90 degrees at the tee instead of feeding into the
> less constricted turning point inside the regulator.
>> Since the fuel pump is a positive-displacement type with excess
>> capacity it's not going to cause *it* a problem, and I find it hard to
>> believe it would constrict flow enough to cause a problem with pressure
> regulation.
>> If you're anal you could test this by installing a tee in place of
>> the existing regulator and measuring pressure at the test tee (not the
>> one you
>> installed) while running the pump with a jumper. If you wanted to be
>> even more persnickety you could then measure the same pressure
>> downstream (toward the tank) of the new tee and subtract it from the
>> other reading to get the true max pressure drop across the tee itself at
> max flow
>> conditions. We're talking about half a liter per minute flow rates here
>> at 35 psi net pressure drop in the system and gasoline's not very
>> viscous, so I really don't see a problem. The tee would have to be
>> fuel and temperature safe at pressure, of course, and if the return
>> line somehow got pinched it might see over 100 psi. A metal tee would
>> take care of any worries there.
>>
>> Yours,
>> David
>>
>
>
>
> --
> Neil n
>
> 65 kb image Myford Ready For Assembly http://tinyurl.com/64sx4rp
>
> '88 Slate Blue Westy to be named.
>
> '81 VanaJetta 2.0 "Jaco" http://tubaneil.googlepages.com/
>
> Vanagon VAG Gas I4/VR Swap Google Group:
>
> http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engine
> s
>
>
--
Neil n
65 kb image Myford Ready For Assembly http://tinyurl.com/64sx4rp
'88 Slate Blue Westy to be named.
'81 VanaJetta 2.0 "Jaco" http://tubaneil.googlepages.com/
Vanagon VAG Gas I4/VR Swap Google Group:
http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines
|