Electric fuel pump

Thigh19

New member
Aug 4, 2019
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I've heard members on this sight talking about electric fuel pumps on carb motors. Is this to prime the regular fuel pump? I've noticed than when I
start my Sequoia after sitting for a while, it's a hard starter. Any recommendations on the fuel pump you all are using? Any tricks will be
appreciated
 
In the use you are contemplating, I use a Carter 4070 electric pump. Plumb
it into the fuel line after the Main/Auxiliary selector valve. Power it
from the positive terminal of the selector valve, so you can select it from
the dash rocker switch. Many people also include a roll over/impact switch
in that circuit. Some wire it into a oil pressure switch, so that if the
engine is not running, neither does the fuel pump. Choice is yours.
Remember, safety first.
Jim Hupy
Salem, Oregon

On Fri, Jan 17, 2020, 12:43 PM Thom High via Gmclist <

> I've heard members on this sight talking about electric fuel pumps on carb
> motors. Is this to prime the regular fuel pump? I've noticed than when I
> start my Sequoia after sitting for a while, it's a hard starter. Any
> recommendations on the fuel pump you all are using? Any tricks will be
> appreciated
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
Here's how I did it:

http://www.gmcmhphotos.com/photos/g6198-cane-9-creek-rv-park-heflin-2c-al.html

Blank flange the mechanical pump opening, and use the adapter on the hard line crossing the frame. Use the existing line to the selector to the tee
on the pumps and put caps on the selector. In this manner you can return to stock by the road in 30 minutes. The relay is powered by the tank
selector. The power it switches to either pump is fed from the ignition bus >through a Ford safety switch from an 05 ranger or an oil pressure
switch>. If you use an oil pressure switch you need to run another wire up from the starter solenoid to the relay to power the pump during cranking.
I use the Ford switch, high G or turnover trips it. The pumps are Mr. Gasket, but toss the supplied filters and fit the Wix replacements. The
originals tend to leak at the swaged seam.

--johnny

--
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
 
I've got the Carter P4070 wired to the fuel selector valve solenoid.
Jim Bounds has a description of this somewhere. It only pumps from the
reserve tank to the fuel select valve, boosting the fuel pressure when needed.
That would be when it's hot in stop and go traffic or driving in the mountains.
I hardly ever use mine except to prime the carburetor after it's been sitting awhile.
--
Bill Wevers GMC49ers, GMC Western States
1975 Glenbrook - Manny Powerdrive, OneTon
455 F Block, G heads
San Jose
 
> I've heard members on this sight talking about electric fuel pumps on carb motors. Is this to prime the regular fuel pump? I've noticed than when
> I start my Sequoia after sitting for a while, it's a hard starter. Any recommendations on the fuel pump you all are using? Any tricks will be
> appreciated

I run the Carter p4070 electric pump.
The cause of your problem could also be fuel bowl leakdown caused by leaking plugs in bottom of carb. This is a common problem, search this site or
Google it. Most people epoxy them.
--
Mike K.
'75 PB
Southeast Michigan
 
Last edited by a moderator:
One of the first things I asked Jim K to do to was to install an electric fuel pump. I should have replaced the carburetor too as we were always
chasing raw gas stink. I've fixed that with the fuel injection. We never had vapor lock but I wanted the electric pump so that we'd never have vapor
lock!
--
Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, Ca
Howell EFI + EBL + Electronic Dizzy
 
Larry
An electric fuel pump will help not to have vapor lock but don’t think you never will.
Especially at high elevations on hot days.
The only way I have finally eliminated vapor lock was a few years ago when I installed in-tank fuel pumps.
Emery Stora

>
> One of the first things I asked Jim K to do to was to install an electric fuel pump. I should have replaced the carburetor too as we were always
> chasing raw gas stink. I've fixed that with the fuel injection. We never had vapor lock but I wanted the electric pump so that we'd never have vapor
> lock!
> --
> Larry Davick
> A Mystery Machine
> 1976(ish) Palm Beach
> Fremont, Ca
> Howell EFI + EBL + Electronic Dizzy
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
We have had good result by pulling the fuel hose straight out side the
frame and connect to the selector valve and a large filter canister then a
rotary vain pump. Not as effective as in tank, but less labor cost.
This works well for carburetor and EFI .
Whenever a pump need to pull/draw volatile fluid, it can induce a column of
vapor.
People that have been misled to believe Fuel injection will solve their
vapor lock issue find it does not.
Having an aux. pump at the tank and away from the heat between the frame
does wonders.
We have been using this concept since 1985 and has worked on my Twin Turbo
EFI as well as my 403 with carb.

On Fri, Jan 17, 2020 at 3:06 PM Emery Stora via Gmclist <

> Larry
> An electric fuel pump will help not to have vapor lock but don’t think you
> never will.
> Especially at high elevations on hot days.
> The only way I have finally eliminated vapor lock was a few years ago when
> I installed in-tank fuel pumps.
> Emery Stora
>
> > On Jan 17, 2020, at 3:48 PM, Larry Davick via Gmclist <

> >
> > One of the first things I asked Jim K to do to was to install an
> electric fuel pump. I should have replaced the carburetor too as we were
> always
> > chasing raw gas stink. I've fixed that with the fuel injection. We
> never had vapor lock but I wanted the electric pump so that we'd never have
> vapor
> > lock!
> > --
> > Larry Davick
> > A Mystery Machine
> > 1976(ish) Palm Beach
> > Fremont, Ca
> > Howell EFI + EBL + Electronic Dizzy
> >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmcrvparts.com
1-800-752-7502
 
Larry
An electric fuel pump will help not to have vapor lock but don?t think you
never will.
Especially at high elevations on hot days.
The only way I have finally eliminated vapor lock was a few years ago when I
installed in-tank fuel pumps.
Emery Stora
 
I feel that most, if not all, of the "vapor lock" issues that we experience
today are NOT ANYTHING WRONG WITH OUR COACHES.
So trying to repair something that is not the root cause of the problem is
a fools errand at best.
In 1957, after I joined the National Guard, completed my basic
training at Fort Lewis, and was attending my first ANACTD UTRA at Yakima
Firing Center in Central Washington. Hotter than the hinges of hades, after
a day on the live fire range, we were cleaning up the 90 mm guns on our
tanks. A 3 striper sent me to the other end of the huge asphalt paved motor
pool for a bore brush with a left handed twist to clean the bore rifling in
our gun. When I got to the other end of the motor pool, I was told that
another company was using it, and I should go to their HQ and see if they
were done with it.
Well, some of you all have already figured this one out. Classic
okey-dokey. They ran my butt all over that 120° black asphalt parking lot,
looking for something that was non-existent. They all had a great laugh at
my expense.
BUT, I NEVER FORGOT THAT LESSON. I grew up a lot that summer. Learned
a bit, too.
DON'T TRY TO FIX NON-EXISTENT PROBLEMS.
Today's gasolines are not blended with the correct viscosity for a
Carburetor. They are formulated to flow through tiny, tiny openings in fuel
injection nozzles at high pressures. They, by design, are much more
volatile than yesterday's gasoline were. Hence, the lower vapor point
index, (they evaporate at much lower temps and pressures).
So, in-tank pumps that push the fuel instead of suck it, are a help.
So is re-routing the the fuel lines to cooler location.
But there is no absolute cure for reformulated fuels. Throw in the
winter/summer blends, a bit of condensed water vapor, alcohol separation,
etc. and your coach will exhibit tendencies that resemble vapour lock. High
temperatures and elevation exaggerates the problem.
Another okey-doke. This one from the E.P.A. They are planning to up
the amount of alcohol blended into the fuel to 15% instead of 10%.
They want you to get rid of gasoline dependent vehicles, and go to electric
vehicles. Guess what? Sale of Electric Vehicles dropped by 7% in 2019.
People that still can think for themselves, aren't buying them. East of the
Rockies, the majority of electricity is produced by fossil fuels and
nuclear energy. You plug in your EV, and you burn up some dinosaurs to
charge it. Quit blowing smoke in my face and telling me that it is good for
me.
RANT OFF.
Jim Hupy
Salem, Oregon

On Sat, Jan 18, 2020, 10:05 AM Fred Hudspeth via Gmclist <

> 'Agree with Emery's experience re in-tank pumps/EFI. No vapor lock at 107F
> ambient (but at only 1500' altitude) - highest temp encountered thus far
> since installation. 'Expect similar performance at 12K' elevation but with
> lower ambient temp...
>
> Fred Hudspeth
>
>
> Fred Hudspeth
> 1978 Royale (TZE 368V101335) - Tyler, TX
> 1982 Airstream Excella (motorhome) - Cooper Landing, Alaska
>
>
>
>
>
>
>
> Message: 6
> Date: Fri, 17 Jan 2020 16:05:19 -0700
> From: Emery Stora
> To: gmclist
> Subject: Re: [GMCnet] Electric fuel pump
> Message-ID:
> Content-Type: text/plain; charset=utf-8
>
> Larry
> An electric fuel pump will help not to have vapor lock but don?t think you
> never will.
> Especially at high elevations on hot days.
> The only way I have finally eliminated vapor lock was a few years ago when
> I
> installed in-tank fuel pumps.
> Emery Stora
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
So the electric fuel pump doesn't need to run all the time? The manual pump will pull fuel through an off electric fuel pump?
 
Three points of clarification regarding the Carter electric fuel pump(s)

1: Keep the solenoid tank selector valve and use one pump OR two pumps
and eliminate the selector valve?

2: If the two pump option is better, do these pumps have internal check
valves so they can be teed into the same line to the carburetor?

and finally (for now)

3: Where should a fuel filter go in this arrangement? Near the tanks or
nearer the carburetor?

Thanks in advance,

Stu

There seems to be a disconnect between the GMCforum and the email list.
Some messages show up here and not there, and vice versa. I suspect a
computer is involved.
 
That's a mattwer of opinion and location and preference. I opted for all electric in my carbureted coach, I'm in the no foolin' hot summer Southeast.
To me, mechanical and electric together represent the worst of both worlds... but as the pics show, my mechanical pump was toast anyway. Lots of
folks opt for the single electric pump, which gives you electric aux tank and mechanical main. For me, that wouldn't likely work - I'd hate to be
pulling Culowee in August and have the mechanical pump be insufficient while the gas left in the aux is all behind the pickup due to the grade. Vapor
lock on that pull, which dam' near put me and the toad over the side, convinced me to do the dual electric thang. Purely personal preference.

--johnny
--
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
 
I believe those Carter pumps have check valves.
Put the filter on the suction side.(between the pump and the tank).

Emery Stora
77 Kingsley
Frederick, CO

>
> Three points of clarification regarding the Carter electric fuel pump(s)
>
> 1: Keep the solenoid tank selector valve and use one pump OR two pumps and eliminate the selector valve?
>
> 2: If the two pump option is better, do these pumps have internal check valves so they can be teed into the same line to the carburetor?
>
> and finally (for now)
>
> 3: Where should a fuel filter go in this arrangement? Near the tanks or nearer the carburetor?
>
>
> Thanks in advance,
>
> Stu
>
> There seems to be a disconnect between the GMCforum and the email list. Some messages show up here and not there, and vice versa. I suspect a computer is involved.
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
On our carbureted Eleganza II I used an inline rotary barrel type 5-6 lb electric pump as a back up and Plumbed on the front (auxiliary) tank and
powered by the reserve tank switch off the solenoid. It only works when the tank is on reserve. On our Crestmont I used the same type pump in line
in front of switching valve and used a manual switch only. Both coaches have stock fuel pumps on engine and I noticed no difference in normal driving
the Crestmont pulling fuel thru the electric pump with it off. Mainly use it to prime carb after sitting for a few months or extra hot days coming
off interstate to traffic lights and fuel seeming to vaporize in carb.

> That's a mattwer of opinion and location and preference. I opted for all electric in my carbureted coach, I'm in the no foolin' hot summer
> Southeast. To me, mechanical and electric together represent the worst of both worlds... but as the pics show, my mechanical pump was toast anyway.
> Lots of folks opt for the single electric pump, which gives you electric aux tank and mechanical main. For me, that wouldn't likely work - I'd
> hate to be pulling Culowee in August and have the mechanical pump be insufficient while the gas left in the aux is all behind the pickup due to the
> grade. Vapor lock on that pull, which dam' near put me and the toad over the side, convinced me to do the dual electric thang. Purely personal
> preference.
>
> --johnny

--
C. Boyd
76 Crestmont
East Tennessee
 
Stu,

The selector valve will very likely suffer "ethanol disease" eventually,
preventing tank selection. It may even fail between tanks and prevent
drawing from either. So why not eliminate that possibility now with two
pumps, preventing that failure and providing pump redundancy. The second
pump should cost little more than a replacement selector.

The Carter 4070 does not require check valves, but I installed them anyway,
just in case I ever have to do a change to some kind that does -- I won't
have to hunt/order check valves at an inconvenient time.

'Most all electric pumps require filters on the input side to protect their
warranty.

Ken H.

On Sun, Jan 19, 2020 at 6:48 PM Stu Rasmussen via Gmclist <

> Three points of clarification regarding the Carter electric fuel pump(s)
>
> 1: Keep the solenoid tank selector valve and use one pump OR two pumps
> and eliminate the selector valve?
>
> 2: If the two pump option is better, do these pumps have internal check
> valves so they can be teed into the same line to the carburetor?
>
> and finally (for now)
>
> 3: Where should a fuel filter go in this arrangement? Near the tanks or
> nearer the carburetor?
>
>
> Thanks in advance,
>
> Stu
>
> There seems to be a disconnect between the GMCforum and the email list.
> Some messages show up here and not there, and vice versa. I suspect a
> computer is involved.
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
Since most of the pumps are rotary , filters are recommended to prevent
excess wear.
Keep in mind, the air that displaces the space as fuel is used is never
filtered, so particulets enter the tank and that is what ends up wearing
the vains in the pump.

On Mon, Jan 20, 2020 at 2:21 AM Ken Henderson via Gmclist <

> Stu,
>
> The selector valve will very likely suffer "ethanol disease" eventually,
> preventing tank selection. It may even fail between tanks and prevent
> drawing from either. So why not eliminate that possibility now with two
> pumps, preventing that failure and providing pump redundancy. The second
> pump should cost little more than a replacement selector.
>
> The Carter 4070 does not require check valves, but I installed them anyway,
> just in case I ever have to do a change to some kind that does -- I won't
> have to hunt/order check valves at an inconvenient time.
>
> 'Most all electric pumps require filters on the input side to protect their
> warranty.
>
> Ken H.
>
> On Sun, Jan 19, 2020 at 6:48 PM Stu Rasmussen via Gmclist <

>
> > Three points of clarification regarding the Carter electric fuel pump(s)
> >
> > 1: Keep the solenoid tank selector valve and use one pump OR two pumps
> > and eliminate the selector valve?
> >
> > 2: If the two pump option is better, do these pumps have internal check
> > valves so they can be teed into the same line to the carburetor?
> >
> > and finally (for now)
> >
> > 3: Where should a fuel filter go in this arrangement? Near the tanks or
> > nearer the carburetor?
> >
> >
> > Thanks in advance,
> >
> > Stu
> >
> > There seems to be a disconnect between the GMCforum and the email list.
> > Some messages show up here and not there, and vice versa. I suspect a
> > computer is involved.
> >
> >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> >
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmcrvparts.com
1-800-752-7502
 
Our experience on rotary electric pump has required a bypass valve when not
operating. If your using a pulse pump, there is no need for a bypass.

On Sun, Jan 19, 2020 at 6:02 PM Charles Boyd via Gmclist <

> On our carbureted Eleganza II I used an inline rotary barrel type 5-6 lb
> electric pump as a back up and Plumbed on the front (auxiliary) tank and
> powered by the reserve tank switch off the solenoid. It only works when
> the tank is on reserve. On our Crestmont I used the same type pump in line
> in front of switching valve and used a manual switch only. Both coaches
> have stock fuel pumps on engine and I noticed no difference in normal
> driving
> the Crestmont pulling fuel thru the electric pump with it off. Mainly use
> it to prime carb after sitting for a few months or extra hot days coming
> off interstate to traffic lights and fuel seeming to vaporize in carb.
>
>
>
>
>
>

> > That's a mattwer of opinion and location and preference. I opted for
> all electric in my carbureted coach, I'm in the no foolin' hot summer
> > Southeast. To me, mechanical and electric together represent the worst
> of both worlds... but as the pics show, my mechanical pump was toast anyway.
> > Lots of folks opt for the single electric pump, which gives you
> electric aux tank and mechanical main. For me, that wouldn't likely work -
> I'd
> > hate to be pulling Culowee in August and have the mechanical pump be
> insufficient while the gas left in the aux is all behind the pickup due to
> the
> > grade. Vapor lock on that pull, which dam' near put me and the toad
> over the side, convinced me to do the dual electric thang. Purely personal
> > preference.
> >
> > --johnny
>
>
> --
> C. Boyd
> 76 Crestmont
> East Tennessee
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmcrvparts.com
1-800-752-7502
 
There are multiple way to install an electric fuel pump and once installed multiple ways to use it.

Some people choose to install 2 pumps, eliminate the mechanical pump, and run one all of the time. In this scenario, additional check and safety
devices are necessary to prevent it from running after a crash or electrical failure. Two electric pumps are necessary in case of a single electric
pump failure which will leave you stranded.

Others like myself, chose use a single electric pump and use it on demand while keeping the mechanical pump for normal operation. It is plumbed like
my airplane and there only for emergencies and to initially fill the carb.

There are advantages to both. My coach fire was not caused by but was sustained by an electric pump that stuck on feeding gasoline everywhere. So
consider why you are installing a pump and find a solution to fit your needs.

I seldom turn mine on but it is there if ever needed.


--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
> I've got the Carter P4070 wired to the fuel selector valve solenoid.
> Jim Bounds has a description of this somewhere. It only pumps from the
> reserve tank to the fuel select valve, boosting the fuel pressure when needed.
> That would be when it's hot in stop and go traffic or driving in the mountains.
> I hardly ever use mine except to prime the carburetor after it's been sitting awhile.

I do what Bill said above, in addition, I have moved the pump, filter, selector valve and fuel hoses to the outside of the frame. I haven't had a
single 'vapor lock' issue since doing that two years ago.
--
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles,
Solar battery charging. GMCSJ and GMCMI member