Vadim,
Before I installed EFI, I installed a "surge tank" (a 12" section of 10"OD
aluminum tube with appropriate ports tapped into the 1/4" thick sides).
Into that, I plumbed the two Carter 4070 (~5 psi) pumps which I'd installed
on the Aux. & Main tanks. The return from that was the one I described
earlier into the Aux. drain plug.
The EFI's high pressure pump is supplied from that surge tank and the
throttle body's return line feeds into that tank. So, I always have ~1
gallon of fuel which has definitely been purged of any vapor available for
the EFI. I've never had vapor lock.
The one change I've contemplated for this system is another high pressure
pump in parallel with the current one -- purely for redundancy.
Ken H.
> I'll definitely keep that in mind. I do have a parts book and a full
> owners manual for our unit. I think I'm good for now.
>
> Another fuel pump related question: I have an '86 BMW which I use as a
> towd. It has one of the most unusual fuel supply setups. It has one fuel
> pump
> in the tank (it is a low pressure pump) and then a high pressure inline
> booster pump for the fuel injection system. Has anyone considered or tried
> to
> use that type of a setup on a GMC? It might be useful with those low
> pressure fuel pump.
>
> > Vadim,
> > You need to not hesitate to ask me for diagrams for your coach so you
> get a
> > better picker and ask. Me for information.
> > I only need to know what info you need,not your private info, so do
> > Not hesitate to call.
> > I have 2-3 people taking care of orders so I can help
> >
> >
> > > My experience with pressure regulators has caused me to use a low
> pressure
> > > pump when needed and not mess with regulators unless your willing to
> pay $
> > > 120 or more
> > > Most of you are expecting high reliability from inexpensive ones, not
> > > major brands.
> > >
> > > On Sat, Sep 29, 2018 at 6:24 PM Vadim Jitkov
> > >
> > >>> Vadim,
> > >>>
> > >>> You probably don't want to do that. The filler tubes enter the
> Aux. and
> > >>> Main tanks at a level which leaves about 6 gallons in the
> non-selected
> > >>> tank. That is, if you run on the Main until the engine dies, you
> can
> > >>> switch to the Aux. and have about 6 gallons of reserve. Or
> vice-versa.
> > >>> That reserve can be lower, due to "sloshing" and steep terrain, but
> you
> > >>> should always have some reserve. With a pump on only one tank,
> you'd
> > >> never
> > >>> be able to access that reserve.
> > >>>
> > >>> A MUCH better idea, IMHO, is to remove the selector valve (which is
> > >> prone
> > >>> to failure under ethanol attack) and install a pump for each tank.
> > >> Select
> > >>> the pump with a relay operated by the disconnected selector valve
> wire.
> > >>> Now you not only have access to all fuel, but redundant pumps as
> well.
> > >>>
> > >>> I DO like your idea of connecting the return to the Aux. tank.
> That's
> > >> what
> > >>> I do. Since I try to always run on Main, I KNOW that I've got
> reserve
> > >> in
> > >>> the Aux. My return is into the drain plug with a guard for that
> pipe
> > >>> bolted to the just-forward crossmember.
> > >>>
> > >>>
> > >>> Ken H.
> > >>> Americus, GA
> > >>> '76 X-Birchaven w/Cad500/Howell EFI & EBL,
> > >>> Manny Brakes & 1-Ton, Troy-Bilt APU, etc., etc., etc.
> > >>>
www.gmcwipersetc.com
> > >>
> > >> With the filler hoses entering tanks as you describe, it makes more
> sense
> > >> now. I was under impression that the AUX tanks just sits a little
> lower and
> > >> that's what leaves some fuel there when main tank runs dry. Thanks
> for
> > >> the explanation.
> > >> --
> > >> Vadim Jitkov
> > >> '76 Glenbrook 26'
> > >> Pullman, WA
> > >>
> > >> _______________________________________________
> > >> GMCnet mailing list
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> > >>
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> > >>
> > > --
> > > Jim Kanomata
> > > Applied/GMC, Newark,CA
> > > jimk
> > >
http://www.appliedgmc.com
> > > 1-800-752-7502
> > >
> > --
> > Jim Kanomata
> > Applied/GMC, Newark,CA
> > jimk
> >
http://www.appliedgmc.com
> > 1-800-752-7502
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> >
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>
>
> --
> Vadim Jitkov
> '76 Glenbrook 26'
> Pullman, WA
>
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