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Good pull through electric fuel pump?

jckkys

Bronco Guru
Joined
Mar 15, 2012
Messages
5,196
Research on classic car sites has produced a possible cure for dried out carburetors on non daily drivers. Some have mounted an electric pump upstream from the mechanical OE pump. They put a switch in a direct battery power supply to the pump to fill the float bowl or bowls. After a few seconds of power the switch is turned off and the engine started. This of course would require an electric pump, that the mechanical one could pull fuel through. Positive displacement pumps may not allow this. Pumps as listed don't specify weather fuel could be pulled through. Has anyone found a good electric pump for this application? A one way valve in a parallel section of fuel line would work too but I would rather not do that if not needed.
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,884
About the only way that would work is with a centrifical pump, and those don't self prime at all.
Just run a Carter P7040 all the time and be done with it.
 
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jckkys

Bronco Guru
Joined
Mar 15, 2012
Messages
5,196
Oddly on the other classic truck and auto sights, no one has a problem with this concept. They also found electric pumps that work in a flow through application. Any pump used this way has to be self priming since in the tank is too impractical. Of coarse centrifugal pumps aren't self priming, so a positive the displacement type must be what they are using. I'm just trying to find witch one. I've never had anything worse than an oil leak with mechanical pumps for nearly 50 yrs. and well over a million miles. Going with electric as a back up makes sense, but electric alone just to fill the float bowls doesn't.
 

Scoop

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Cuchara, CO
I've run that setup on a number of vehicles. I use to use a Carter but lately I've used a cheap (~$40) Mr Gasket pump. Works well and the mechanical pump pulls through it easily.
 
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jckkys

Bronco Guru
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Mar 15, 2012
Messages
5,196
That's good news. I looked at some in stock at a local speed shop. Of the low pressure pumps appropriate for carburetors, I couldn't find one air could be sucked through easily. If air can't get through, neither can gas. What Mr. Gasket pump do you use? What's the "Scoop"? Longevity isn't an issue. It will only be run for a few seconds after the Bronco sits for more than a few days or if the mechanical dies.
 

chuck

Bronco Guru
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Aug 14, 2001
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Ingram, Texas
That's good news. I looked at some in stock at a local speed shop. Of the low pressure pumps appropriate for carburetors, I couldn't find one air could be sucked through easily. If air can't get through, neither can gas. What Mr. Gasket pump do you use? What's the "Scoop"? Longevity isn't an issue. It will only be run for a few seconds after the Bronco sits for more than a few days or if the mechanical dies.
I thank you should try whatever pump you want to use. I have played with a lot of pump combos over the years and have yet to fine a pump that will not allow fuel to pass in one direction and not in the other. I have not tried all pump combos but with my luck I thank I would have come across one that was diff. Stock pumps will collapse a fuel tank if allowed and suck fuel right through the rotor or vib pump. On our racer we ran two hp pumps for EFI in series and switch back and forth with no problems they are within 1 foot of each other.
 

broncnaz

Bronco Guru
Joined
May 22, 2003
Messages
24,341
In my expericance the mr gasket pumps are crap. IMO It would probably be a waste of money for as little use as it will see.
Ive had much better luck with carter P4070's Ive only seen one fail in over 30 years. Just not sure how well you can pull fuel thru a carter pump. I'd just run the electric and be done.
 

Scoop

Contributor
Have Bronco, Will Travel
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Feb 1, 2006
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10,604
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Cuchara, CO
Two of my 4 Broncos have Mr Gasket pumps in them. One as a feeder to a high pressure efi pump and 1 to a carb set up. Only had 1 issue with a pump - in one temporary set up I left power on to the pump overnight and it froze up. My fault and O'Reilly's still replaced it. The one in my trail rig is a Carter has been working good 10 plus years first in a carbed set up and now in the efi system. Granted the Carter is probably a better pump but I've had good luck with the Mr Gasket pumps too.
 

baddad457

Sr. Member
Joined
Aug 24, 2011
Messages
560
I've been running the MrGasket 12S in my 77 Comet now for 6-7 years. Never had a problem with it feeding THREE carbs (3x2 setup) on a 400+ HP 331. Also ran the Purolator pump of the same design for nine years in a V8 89 Ranger. With either of these pumps you can ditch the mech pump altogether and save some HP loss.
 
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jckkys

Bronco Guru
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Mar 15, 2012
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5,196
I'm not going scrap the mechanical pump. No reason to fix what isn't broken. The nature of utility required by classic auto insurance prohibits daily drivers. The OE type pump works perfectly when the float bowl is full. A week in winter and two days in summer, are all it takes to dry out the carb. 5-10 seconds of cranking and it starts. Electrics may be dependable but the mechanical has proven totally dependable. It also looks correct in a vehicle that was never built with anything else. The starter works less than 1/2 second when the carb is full. I want that same quick start after it sits a few days. The electric I'm looking for would not create a pressure differential down stream as fuel is moves through and no electric power is supplied.
 

chuck

Bronco Guru
Joined
Aug 14, 2001
Messages
6,474
Loc.
Ingram, Texas
I agree with the manual pump. That is why I was saying to use any elec. pump. Should prime the carb when you need it.
 
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