[Supras] Dual Walbros

[Brandon]

they are suppose to, yes.  A buddy of mine just went throught the same thing 
on the GS300 w/ the GTE swap hes building, went to check the fuel system and 
had little to no pressure because one of  pumps was dead.  Yes they were 
walboros.   I've seen this on almost all of the upgraded pump, where they 
won't retain pressure when there off.   As far as leaning out, yes its only 
a problem if your in the area where you needed two fuel pumps, but if you 
installed two, then you probabbly needed two, so that means it would be a 
risk there if one pump died and on didn't.

----- Original Message ----- 
From: "Jim Jobe" <jjobe2 at supratech.org>
To: "Brandon" <fstrnldr at tconl.com>
Cc: "Rockey Fox" <supr91tt at yahoo.com>; "sprigmo1" <sprigmo1 at yahoo.com>; "car 
club" <supras at supras.com>
Sent: Wednesday, August 30, 2006 7:58 AM
Subject: Re: [Supras] Dual Walbros


>
> In tank fuel pumps have internal check valves.
>
> If one pumps dies the engine will only run lean where the fueling 
> requirements
> exceed the volume of one pump - high boost >5-600 rwhp.  Below that there
> should be no change in fueling.
>
> On Wed, Aug 30, 2006 at 02:42:45AM -0500, Brandon wrote:
>> Yes if one pump fails, then the remaing pump will pump through the dead 
>> pump
>> back into the fuel tank.  Check valve would be a bad idea .... if you are
>> tuned using twin pumps and one dies, but the other remains you are going 
>> to
>> go very lean, but if one dies and you lose 98% of your pressure the 
>> engine
>> should just die, and be fine to run again when the pump issue is 
>> resolved.
>> If you are that worried about a pump dying, a manual valve would be the 
>> way
>> to go, then you could shut down the dead pump and limp it home on the
>> remaining.
>>
>> ----- Original Message ----- 
>> From: "Rockey Fox" <supr91tt at yahoo.com>
>> To: "sprigmo1" <sprigmo1 at yahoo.com>; "car club" <supras at supras.com>
>> Sent: Tuesday, August 29, 2006 8:56 PM
>> Subject: Re: [Supras] Dual Walbros
>>
>>
>> > Are the dual pumps needed for redundancy or volume?
>> > I'm not sure of the Walbro pump design and how it acts
>> > when not energized but running in series may seriously
>> > restrict fuel flow if one of the pumps failed. On the
>> > other hand if in parallel, if one of them fails will
>> > your fuel flow back through the dead pump which would
>> > be the path of lesser resistance instead of
>> > maintaining desired (or required) pressure to your
>> > FPR?
>> > Personally if I were installing two fuel pumps I would
>> > consider a check valve downstream of each pump and run
>> > them in parallel to a common line past the back flow
>> > preveter (check) valves and then to the FPR.
>> >
>> > Just an uninformed opinion on this one, but an
>> > interesting thought,
>> >
>> > Rockey 91T
>> >
>> >
>> > --- sprigmo1 <sprigmo1 at yahoo.com> wrote:
>> >
>> >> Anyone have the wiring schematic for running dual
>> >> Walbros?  I just got my second pump and want to
>> >> install it before I get my new turbo!
>> >>
>> >>   Malik
>> >>   It Ain't Eazy Being Me!!!!
>> >>   92Trbo Supra
>> >>
>> >>
>> >>
>> >>
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