Electric Fuel Pump

[edgar t. kremer]

I posted the note you refer to. I am using an electric pump sold by Chuck
Stoddard. I don't believe he still sells the same model. One thing to look for
is a pump that will allow you to "pull through" when it is not operating. This
type will not impede fuel flow. As you quoted, I ran for years with this
setup, using the electric pump only to prime the carb & overcome vapor lock. I
don't know if Stoddard's current pump fills the bill.

> GMCers
>
> I would like to get the part number for a good electric fuel pump.
> Now here is the kicker. I really dont intend to use the electric pump.
> I just would like to be able to prime the carb after not running for a
> long time. I would also like to be able to overcome vapor lock problems.
> I intend to run on the mechanical pump most of the time. The electric
> one would also be a nice back-up.
>
> Now here is my problem. People around me who should know are
> giving me conflicting information. The problem some of them say
> is that the electric pump will impede the fuel flow. This will cause
> problems.
> I know somebody here posted a note saying they had added an
> electric pump and ran for years on the mechanical one with no problems.
> I would love to hear a part number for an electric fuel pump that would
> work in this manor.

 

[richard guthart]

Arch,

(1) I did a little research recently and decided to install the Holley street
pump (Model 12-801) that is preset at 7 psi. Here it is:
http://www.holley.com/HiOctn/ProdLine/AV/FMS/FMSFP/12-801.html. BTW this pump
draws less than 3 amps. I got it from Summit Racing (stock number HLY-12-801)
for $64.50.

I placed it immediately downstream from the fuel tank selector valve. For now
the mechanical pump is still in the line, and this is the way I ran during a
recent 400 mile trip, but I intend to remove the mechanical pump when I get time
to do it.

I don't know if the mechanical pump would draw through the Holley with the
Holley shut off. (Holley has a tech line.)

(2) Last time I was in Eaton GMC I looked at the electric pump they install as
either a booster or replacement for the mechanical ones. They get it from
Caspro. It's made by Carter, and also is in the Summit Racing cat. Page 72
(stock number CRT-P4070), 5 psi, street. $49. Current draw is 4.5 amps. There's
also a 7 psi version for $49.50. The spec sheet that came in the box with this
Carter pump specifically said that it was not suitable for applications where
you want to draw through it. BUT, the mechanic at Eaton GMC has been using one
on another vehicle exactly as you intend, and says the mechanical pump draws
through it just fine. So I don't know what to tell you.

(3) I know that GMCers have taken different approaches to this, but my rationale
for replacing the mechanical pump with an electric one was a) to reduce the
potential for vapor lock and b) provide for fuel shut-off in the event of a
sudden loss of oil pressure (the pump is wired through an oil pressure safety
switch.)

Hope this helps,

Richard

From:
To:
Sent: Sunday, July 11, 1999 7:27 PM
Subject: GMC: Electric Fuel Pump

> GMCers
>
> I would like to get the part number for a good electric fuel pump.
> Now here is the kicker. I really dont intend to use the electric pump.
> I just would like to be able to prime the carb after not running for a
> long time. I would also like to be able to overcome vapor lock problems.
> I intend to run on the mechanical pump most of the time. The electric
> one would also be a nice back-up.
>
> Now here is my problem. People around me who should know are
> giving me conflicting information. The problem some of them say
> is that the electric pump will impede the fuel flow. This will cause
> problems.
> I know somebody here posted a note saying they had added an
> electric pump and ran for years on the mechanical one with no problems.
> I would love to hear a part number for an electric fuel pump that would
> work in this manor. I would also like to hear what mechanical pumps
> work best. Yes, I have the cross over list----it does not tell me which is
> best. Then I would like to hear about anybody's experiences with spin
> on gas filters. Yeah I want to do that too. If you cant tell I am into the
> fuel system this week. Fuel tanks are done, all fuel lines are replaced.
> If any of you have any other suggestions of things I should look at while
> everything is clean and new I sure would like to hear from you. The tanks
> are still down so the time is good to do anything else I should do.
> Sure would like to hear from any of you who have done this. BTW it sure
> is fun running around with the old 455 hooked to a 6 gallon boat tank.
> You can really watch the fuel gauge go down if you jackrabbit start it
> from a stop sign. Thanks in advance.
>
> Take Care
> Arch 76 GB IL
>

 

[richard guthart]

Larry,

A month or 2 ago I asked a bunch of questions about fuel line pressure.

Here's an excerpt from a response from Rick Staples which I found to be very
helpful:

> As for selecting a pump, remember: the Quadrajet should never see over 6
> psi pressure, lest it flood over. According to Doug Roe (ROCHESTER
> CARBURETORS, HP Books, p. 116) the preferred pressure is 4 - 6 psi. Better to
> be a little below 4, than over 6.....

The Holley tech people assured me that their 7psi pump would provide the correct
fuel inlet pressure when you take into account the normal pressure drop between
the pump and carb, which in my application are separated by about 18 feet of
fuel line and the filter at the carb inlet.

Richard

- ----- Original Message -----
From:
To:
Sent: Monday, July 12, 1999 8:41 AM
Subject: Re: GMC: Electric Fuel Pump

> Arch, good luck with your fuel pump experiment. I had disconnected mine
> during some maintenance wherein I had to have the ignition on for a while,
> and was tired to listening to it working away. As you might guess, I forgot
> to put the 12+ lead back on the pump and left for a trip. Couldn't figure out
> why she didn't want to go up the hills in Springfield. Finally remembered
> about the pump and everything was fine. I believe that the pump DOES impede
> fuel if it is OFF. I am considering a by-pass around the pump and a dash
> switch to kick in the pump when necessary. I wonder if having the pump on all
> the time gives the carb more fuel than it really needs, and thus it ends up
> burning it. Just the theory of a dumb guy. Larry in MO, 75 PB
>

 

[john wright]

The electric fuel pump sold by Caspro is a Carter P4070. It is $89 +
S&H from him or you might find it at you local Autoparts place at a
lesser price.

J.R. Wright
GMC GreatLaker
77 Eleganza II
Michigan

>
> I posted the note you refer to. I am using an electric pump sold by Chuck
> Stoddard. I don't believe he still sells the same model. One thing to look for
> is a pump that will allow you to "pull through" when it is not operating. This
> type will not impede fuel flow. As you quoted, I ran for years with this
> setup, using the electric pump only to prime the carb & overcome vapor lock. I
> don't know if Stoddard's current pump fills the bill.
>

>
> > GMCers
> >
> > I would like to get the part number for a good electric fuel pump.
> > Now here is the kicker. I really dont intend to use the electric pump.
> > I just would like to be able to prime the carb after not running for a
> > long time. I would also like to be able to overcome vapor lock problems.
> > I intend to run on the mechanical pump most of the time. The electric
> > one would also be a nice back-up.
> >
> > Now here is my problem. People around me who should know are
> > giving me conflicting information. The problem some of them say
> > is that the electric pump will impede the fuel flow. This will cause
> > problems.
> > I know somebody here posted a note saying they had added an
> > electric pump and ran for years on the mechanical one with no problems.
> > I would love to hear a part number for an electric fuel pump that would
> > work in this manor.

 

[jimbiava]

part number for a good electric fuel pump. NAPA # P74019 & INLINE
FILTER NAPA # 3048BP &
# 3040BP one filter is with bypass and the other is inline (large) use
before pump.
> I intend to run on the mechanical pump most of the time. The electric
> one would also be a nice back-up.
This pump is a 7 to 9 psi pump, use between fuel selection valve and
mechanical pump. Yearwood Speed and Custom presure gauge # HOL26 500. I
cut an exact sized hole for the presure gauge face to fit up into the
floorboard, so as to watch presure while driving and so as to not have fuel
system in passanger compartment. I run the pump with ignition switch.
Raton Pass...pulling trailer, loaded and top out at 55 mph or better, have
not lost power in extreme heat since I completed the improvements I listed
to this group last year.

>
> Now here is my problem. People around me who should know are
> giving me conflicting information. Ed Osborn supplied me with a simular
Pump part no. but could not get it.
" the electric pump will impede the fuel flow." will not!
> Arch 76 GB IL

Nice to see you again Arch!
JimBiava
used to be Yoogeebear...no longer putten up wit da aol!