1954 Mercury Fuel Issue

[JMFL36]

Hi folks. I have a '54 Mercury Monterey, all stock, that I am having a fuel supply issue with. Under regular use, the car starts and runs fine on both cold and hot starts. But the longer the car sits between starts, the more I have to crank it to get gas to the carburetor. This car has a recently rebuilt dual action gas/vacuum pump with the gas pump on top and a glass sediment bowl above the pump. It seems like I'm losing prime or pressure in the fuel line until the pump has a chance to restore it. Any suggestions on causes or fixes would be appreciated.

[dmsfrr]

Are you using the currently available pump gas blended with ethanol or a non-ethanol version?

Did the pump rebuilder use an ethanol compatible rebuild kit.

https://www.pure-gas.org/

[JMFL36]

Originally Posted by dmsfrr

Are you using the currently available pump gas blended with ethanol or a non-ethanol version?

Did the pump rebuilder use an ethanol compatible rebuild kit.

https://www.pure-gas.org/

I only use ethanol-free gas in all my classic cars.

[KULTULZ]

A mechanical pump is only going to hold line pressure for a short while. Usually, the fuel in the bowl will allow starting until the pump re-primes.

After it sits for a few days, remove the air cleaner -

Open the choke valve and with a light see if there is gasoline puddled in the intake manifold plenum ...

Operate the the throttle lever. Do you see fuel injected into the throttle bores?

There were problem(s) with heat soak and evaporation even back then.

[Daves55Sedan]

It might be recommended to get Sal Scicala in on this issue.
On the '51 thru '56 Fords with 2-bbl carbs, the carburator (Ford B8A or, EBU, Holley 2100, Holley 2110 ECG style carbs) is often at fault as they tend to leak the gas out of the float bowl after a couple days. Often, it is because the power valve diaphragm has a little crack, or the power valve gasket is leaking. If you start and run your car everyday, you would never know a problem existed. But I think the Mercury V8's had a teapot style carb, and I don't have familiarity with them.

[scicala]

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Other than evaporation, I have no explanation on how gas disappears in the carb bowl on a teapot style Holley. There should be enough fuel in the bowl after a few days to start the engine, provided the choke is set correctly and the accelerator pump is working.
The teapot power valve is all brass with no diaphragm. Plus the fuel valve is above the fuel level making it impossible for the fuel to backflow and empty the bowl. There are also anti siphon holes (air bleeds) on the bowl cover for the rear barrel fuel supply.

I have heard of complaints when using fuel with 10% ethanol due to evaporation.

Sal

[JMFL36]

I am running one of Sal's teapot carbs on my Mercury. If I pour a little gas down the barrels the car fires right up. If I don't I have to crank it quite a bit to get it to fire. The longer it's been sitting, the longer I need to crank it. Sal, any suggestions?

[scicala]

Originally Posted by JMFL36

I am running one of Sal's teapot carbs on my Mercury. If I pour a little gas down the barrels the car fires right up. If I don't I have to crank it quite a bit to get it to fire. The longer it's been sitting, the longer I need to crank it. Sal, any suggestions?

If you're using non ethanol fuel, and it's only been a few days since it was started, I don't really know why. I know an electric fuel pump helps avoid all of the extra cranking to fill the carb, but really shouldn't be needed. It wasn't back in the day.

Sal

[JMFL36]

Although I hate to do it, does anyone have a recommendation for a good 6 volt priming electric fuel pump?

[56 Panel]

You can try this company. Southeastern power products Pompano beach florida
954 979 5899. They sell facet electric pumps. Hope this is a help.

[Daves55Sedan]

Originally Posted by JMFL36

does anyone have a recommendation for a good 6 volt priming electric fuel pump?

AIRTEX #E8902, 6-volt, 2.5-4 psi. They also offer one with a higher output but my choice would be to stick with the 2.5-4 psi model if I were ever going to install one. You could probably order this right out of RockAuto.com

[GLAmes]

Originally Posted by Daves55Sedan

AIRTEX #E8902, 6-volt, 2.5-4 psi. They also offer one with a higher output but my choice would be to stick with the 2.5-4 psi model if I were ever going to install one. You could probably order this right out of RockAuto.com

Is this somehing that would be a pusher pump to the stocker or a replacement?

[KULTULZ]

Originally Posted by GLAmes

Is this somehing that would be a pusher pump to the stocker or a replacement?

Either according to plumbing and intended usage.

- https://airtexasc.com/blog/im-positive-its-negative/

[KULTULZ]

I know an electric fuel pump helps avoid all of the extra cranking to fill the carb, but really shouldn't be needed. It wasn't back in the day.

They were used back in the day as the same problem(s) were there also (except for E-10 gasoline).

I had a 1958 LINC AD that described the problems and have lost it.

[JMFL36]

A couple of questions when plumbing and wiring these Airtex auxiliary pumps. Plumbing - Do folks usually put shutoff valves on either side of the pump for ease of servicing and fuel filter changes? Does the Airtex provide enough flow-thru when switched off? I want to use it as a priming pump only. Wiring - Do folks usually wire the pump to an under-dash toggle switch and then to an ignition-on power source? Thanks in advance, John

[KULTULZ]

Here is a basic tutorial - http://www.how-to-build-hotrods.com/...fuel-pump.html

Read this and get back for particulars.

[Robz51]

I use an electric pump in my 52 merc to prime the teapot carb. I also have a 51 Ford with a 302 and an edelbrock 4bbl that does the same thing. An electric pump helps freatly.
Rob

Sent from my SM-G960U using Tapatalk

[JMFL36]

If I'm using a momentary toggle switch to turn on the pump (to prime the teapot), do I really need to worry about including a relay powered through an ignition power source and an oil pressure sensor as described in the diagram? I was just going to wire from a battery power source to a momentary (spring-loaded) toggle switch to the pump.

[GLAmes]

Originally Posted by JMFL36

If I'm using a momentary toggle switch to turn on the pump (to prime the teapot), do I really need to worry about including a relay powered through an ignition power source and an oil pressure sensor as described in the diagram? I was just going to wire from a battery power source to a momentary (spring-loaded) toggle switch to the pump.

In that application there would have to be free flow of gas through the pump while it isn't running. I think that a non-running pump wouldn't let fuel flow through it.

[Daves55Sedan]

Originally Posted by GLAmes

In that application there would have to be free flow of gas through the pump while it isn't running. I think that a non-running pump wouldn't let fuel flow through it.

That depends on how you pipe up the electric pump. I like the idea of using a spring return to off toggle switch to operate the pump just long enough to prime the carb.
The scenario I had in mind if I were going to add an electric pump would be to cut the metal tubing off near the gas tank outlet and loosen the fitting that goes into the tank so that the "elbow" is turned sideways toward the driver side frame rail. Cut off all that tubing that runs upward along the floor of the car. Install the filter and pump horizontally in a bypass fashion below the main fuel line with a check valve in the main line above the pump so that when the pump is operated it doesn't push fuel in a loop, but forces the fuel forward to the original mechanical fuel pump and up to the carb. Add a little bit of tubing to connect the output to the main fuel line along the frame side-rail. Some compression fittings would also be required for an installation like this. When the electric pump is off and the engine is running off the mechanical pump, fuel flows thru the main line, thru the check valve and bypasses the electric pump altogether.