Electric fuel pump

[TodFitch]

I am considering installing an electric fuel pump back by the tank to cover two situations:

• Priming the carburetor if the car has been sitting a long while.
• Quickly recovering from fuel pump vapor lock.

I want to run mostly/always on the original mechanical pump so want an electrical pump that would allow the original pump to pull through without too much restriction. I would power it from a momentary contact switch, maybe hidden under the dash. And, of course, it needs to work on a 6v positive ground electrical system.

 

Any recommendations on brand and/or model of pump to look for?

[knuckleharley]

I don't know if I can recommend them or not beause they are the only brand of aftermarket electric fuel pumps I have ever used,but I bought 2 from Summit Racing for my two 51 Fords,and believe I paid 36 bucks each for them.

 

Being more than a little anal and a little paranoid,I also bought in-line adjustable fuel pressure regulators even though the fuel pumps only pump MAYBE 6 PSI at peak pumping. I just like to KNOW what is going on.

 

Summit Racing can give you more info on them. They are standard items there,so should be easy to find.

 

The fuel pressure gauges are just me being anal. Most people probably don't feel the need for them with standard low pressure pumps,but like I said above,I tend to be a little obsessive about items that MIGHT cause the base to flood with gas,or an engine fire under the hood. Had a underhood engine fire with my P-15 coupe due to a backfire while driving down the road ,and don't recommend the experience to anyone.

 

BTW,in that case,the modern OHV engine was running the stock mechanical fuel pump. 

Edited January 8, 2021 by knuckleharley

[maok]

I had an expensive SU (Facet) style electric pump on my '28 for 12 months before it gave up, I now have a cheap Chinese pump ($15) that has lasted at least 3 years now, still going. My pump is running full time. I too have a regulator, set at 2.5psi.

[ccudahy]

The setup that has been recommend to me is a Carter P4259 6 Volt Electric Fuel Pump with a Holley 12-804 Adjustable Fuel Pressure Regulator, 1-4 PSI and a 0-15 psi liquid filled pressure gauge in the engine compartment, to make sure its set around 2-3 psi. The old carburetors not like to much pressure. I was told this electric pump works well with the mechanical fuel pumps. I personally have not used this setup, yet. Just info I have squirreled away "just in case".    

Edited January 8, 2021 by ccudahy

[Merle Coggins]

I got an inline 6v pump from MACs a while back, but when I search their site now I can only fine 12v versions. I believe it was Airtex and has a pressure rating of 2.5-4.5 psi. This won't put out too much pressure for your carburetor so you won't need a regulator. I mounted it inline near the tank and used it as you describe. I found that I sometimes had to crank the engine for a couple seconds to get the pump to start pushing fuel through the mechanical pump for priming. I'm not sure why, unless it can't push fuel through if the diaphragm is in a certain position. I also found it good on very hot, after a short shut-off condition, when the mechanical pump would struggle to pump. I could switch on the electric pump and everything would smooth out. After I'd get moving again, to get good air flow through the engine compartment, I could switch the pump off and continue on. My switch is double throw, on-off-momentary. I have it wired so it'll activate the pump either way. 

 

Recently I replumbed it to have a parallel line from the electric pump that bypasses the mechanical one. It still works the same way but primes up every time without needing to give it a short crank. I also figured this would be a better backup if the mechanical pump failed.  

 

My pump looks like this

Edited January 8, 2021 by Merle Coggins

[Pete]

Carter bought Airtex and is discontinuing the Airtex products. I spoke to a Carter tech support guy. He seemed to be an honest person (!) who told me that Carter will be happy to sell you a "6v" electric fuel pump, but that their 6v and 12v pumps are the same part number. Also they will likely discontinue the impulse pumps. These changes have apparently occurred within the past year or so.

 

I run Airtex 6v low pressure impulse pumps on my two old Mopars. Last year I ordered another impulse pump as a backup. It was branded as Airtex, but was different. I've never had an issue with the 2 pumps installed on my vehicles.

 

I had previously tried the Carter rotary pump, but I found it obnoxiously loud. Also, I mostly use the electric pump for priming the carb, then turn it off and run using the mechanical pump. I found that the rotary pump restricting the fuel flow to the mechanical pump when it was shut off. I have not had that issue with the impulse pumps.

 

Pete

 

[knuckleharley]

I just checked the listed 6 volt pumps in the Summit Racing online catalogue and didn't see the Airtex listed,but I did see this one.

 

https://www.summitracing.com/parts/gmb-599-1380

 

Brand: GMB North America

Manufacturer's Part Number: 599-1380

Part Type: Fuel Pumps

Summit Racing Part Number: GMB-599-1380
 

UPC: 083286195233

 

GMB North America 599-1380

•  
• View All Media

• 

$24.99

 

I strongly suggest if you prefer an airtex to call them or send them an email asking about parts and availibility on other 6 volt electric fuel pumps.

[DJK]

I am using the Carter 6v pos ground fuel pump, no regulator, manual pump delete, 3500 miles this past summer, no issues. I installed a switch to shut the pump off prior to shutting of engine to drain carb., also installed a Ford inertia switch in the trunk in case of collision.

[knuckleharley]

44 minutes ago, Pete said:

Carter bought Airtex and is discontinuing the Airtex products. I spoke to a Carter tech support guy. He seemed to be an honest person (!) who told me that Carter will be happy to sell you a "6v" electric fuel pump, but that their 6v and 12v pumps are the same part number. Also they will likely discontinue the impulse pumps. These changes have apparently occurred within the past year or so.

 

I run Airtex 6v low pressure impulse pumps on my two old Mopars. Last year I ordered another impulse pump as a backup. It was branded as Airtex, but was different. I've never had an issue with the 2 pumps installed on my vehicles.

 

I had previously tried the Carter rotary pump, but I found it obnoxiously loud. Also, I mostly use the electric pump for priming the carb, then turn it off and run using the mechanical pump. I found that the rotary pump restricting the fuel flow to the mechanical pump when it was shut off. I have not had that issue with the impulse pumps..

 

Pete

 

Learn something new every day.

 

Thanks!

[Knaveofdarts]

Great info here, thanks for the questions + answers.

[Sam Buchanan]

49 minutes ago, DJK said:

I am using the Carter 6v pos ground fuel pump, no regulator, manual pump delete, 3500 miles this past summer, no issues. I installed a switch to shut the pump off prior to shutting of engine to drain carb., also installed a Ford inertia switch in the trunk in case of collision.

 

My P15 has no momentary switches, bypass lines, pressure regulators or gauges, or antique mechanical pump leaks. The fuel system is one place where additional complexity is not a good thing. ?

 

I do agree the Carter rotary pump can make a little noise. Here is how I soft-mounted mine so the only time I hear it is when I first turn on the ignition...the sound tells me the pump is running. After engine start I no longer notice it.

 

Edited January 8, 2021 by Sam Buchanan

[55 Fargo]

1 hour ago, Merle Coggins said:

I got an inline 6v pump from MACs a while back, but when I search their site now I can only fine 12v versions. I believe it was Airtex and has a pressure rating of 2.5-4.5 psi. This won't put out too much pressure for your carburetor so you won't need a regulator. I mounted it inline near the tank and used it as you describe. I found that I sometimes had to crank the engine for a couple seconds to get the pump to start pushing fuel through the mechanical pump for priming. I'm not sure why, unless it can't push fuel through if the diaphragm is in a certain position. I also found it good on very hot, after a short shut-off condition, when the mechanical pump would struggle to pump. I could switch on the electric pump and everything would smooth out. After I'd get moving again, to get good air flow through the engine compartment, I could switch the pump off and continue on. My switch is double throw, on-off-momentary. I have it wired so it'll activate the pump either way. 

 

Recently I replumbed it to have a parallel line from the electric pump that bypasses the mechanical one. It still works the same way but primes up every time without needing to give it a short crank. I also figured this would be a better backup if the mechanical pump failed.  

 

My pump looks like this

Thanx for the info Merle.

This pump is same on 12 vdc I take it.

On my 318 with mechanical fuel pump, Carter BBD 2 bbl carb same issues.

If i dont start engine after a day or so gotta prime carb or lots of cranking. Headscratching thing is I use non ethanol fuel too. So either the bowls are drying up fast or fuel is back siphoning.

With a prime she fires instantly, no problem in hot weather I have noticed yet, but sure there will be.

 

[48ply1stcar]

Todd

I added a Carter P4259 (Shown above by Sam) and then bought a new mechanical pump and haven't needed it.  I plumbed the Carter parallel like the photo below, but not a neatly.  The parallel line also has a one-way vavle so that when the electric pump in on it doesn't pump back into the fuel tank.  Additionally, The fuel pump is operated by a switch in the car and a oil presure switch on the motor to shut off curent to the fuel pump when the engine dies.

[keithb7]

This 6V pump seen below worked well. It got me out of a bind a couple times. Roadside.  Then later for troubleshooting too. Back when I was learning all about these old cars, and what was going on with my fuel system. 
 

I finally figured out a couple of things. I JB-welded my mechanical pump fulcrum pin in place. I learned to only  run non-ethanol fuel. I figured out where my fuel gauge sat when the tank was bone dry. Then I never needed the electric pump much. I flip it on to prime the system when the car has been sitting for a week or so. That’s about it.  The old mechanic pump seems to be doing well, once I rebuilt it. 
 

 

Edited January 9, 2021 by keithb7

[55 Fargo]

Here's something I have pondered, if the electric pump is used to prime or in a heated fuel issue.

The fact the pump is not being pumped often but has fuel running through it, will its innards be prone to premature wear for any reasons?

[TodFitch]

1 hour ago, 55 Fargo said:

Here's something I have pondered, if the electric pump is used to prime or in a heated fuel issue.

The fact the pump is not being pumped often but has fuel running through it, will its innards be prone to premature wear for any reasons?

I don't think so.

 

The inlet and outlet check valves should see the same flow when gas is pumped by the electric as when the pump itself is doing the work.

 

The spring loaded diaphragm that runs off the cam to pump the gas will be held in the pressurized position. Which actually means there is likely a bit less wear on things like the actuating arm, pivot points, etc.

[Sam Buchanan]

1 hour ago, 55 Fargo said:

Here's something I have pondered, if the electric pump is used to prime or in a heated fuel issue.

The fact the pump is not being pumped often but has fuel running through it, will its innards be prone to premature wear for any reasons?

 

I understood this question to be in regard to whether or not the life of the electric pump would be shortened by intermittent use.

 

I don't know for certain....but I doubt it. I can tell you that on my aircraft the Facet electric diaphragm pump that is only used for takeoffs and landings as a backup to the mechanical pump is still working fine after twenty-one years in service. The full-time mechanical pump has been replaced twice.  ?

[55 Fargo]

9 hours ago, TodFitch said:

I don't think so.

 

The inlet and outlet check valves should see the same flow when gas is pumped by the electric as when the pump itself is doing the work.

 

The spring loaded diaphragm that runs off the cam to pump the gas will be held in the pressurized position. Which actually means there is likely a bit less wear on things like the actuating arm, pivot points, etc.

Are you referring to the Mechanical or Electric pump Tod?

Sounds like yours and Sam's post cleared it up...thanx

[Ernie Baily]

Hello, I bought a low pressure electric pump from Randy at The Fifth Avenue Garage to work with the stock pump to resolve the vapor lock that was happening during summer on my 48 Plymouth. Now with the new optima battery and Petronics electronic ignition, the car works great!

[47 dodge 1.5 ton]

Does anyone know with a gauge what the stock mechanical pump produces? Does it do the same at idle verses 2000 rpm? I am going to need this route and was looking at 12v pumps. 

[Merle Coggins]

3-5 psi.

[55 Fargo]

Just started my 318 this evening after 5 days.

Tried the crank a few times, wait then crank a few times.

It started after 4 or 5 such cycles.

If I prime bowl it fires immediately.

Gonna add an electric for priming, just gonna have to be this way..

[Bryan]

On 1/8/2021 at 7:55 PM, 48ply1stcar said:

Todd

I added a Carter P4259 (Shown above by Sam) and then bought a new mechanical pump and haven't needed it.  I plumbed the Carter parallel like the photo below, but not a neatly.  The parallel line also has a one-way vavle so that when the electric pump in on it doesn't pump back into the fuel tank.  Additionally, The fuel pump is operated by a switch in the car and a oil presure switch on the motor to shut off curent to the fuel pump when the engine dies.

What is the part on the parallel line?  Wonder if this would be easier than running a return line to the tank?

[oldodge41]

If it is a one way or check valve it is to prevent fuel taking the path of least resistance back to the fuel tank. Not a substitute for a fuel return line.

[Sniper]

I believe the check valve is only used when you are also running a mechanical pump.  Some electric pumps won;t allow a mechanical pump to draw thru them.  So if you have an electrical pump that you only use to prime the carb and you have one of those non-draw thru electrical pumps sharing the same pickup you need the check valve to allow the mechanical pump to draw gas.