Gas drain back

[Cornpatch MO]

318 2 bbl. 1968 Satellite... If the car sits for a few hours, evidently the gas siphons back out of the fuel bowl. Takes too much cranking to get gas back in the carb. Sitting for a short time, the car starts right up. Never have a problem with vapor lock when engine is hot. I don't want to change fuel pump or install an inline electric fuel pump.
Anyone know if there is a one way valve that could be installed in the fuel line between the carb and fuel pump? ...............MO

 

[oldkimmer]

It’s probably percolating the fuel out of the carb into the intake. Try holding it to the floor to start it. Kim

 

[HALIFAXHOPS]

Can also be the check valve in the fuel pump sorry man. I am sure there is a suitable check valve available but would really think about it before doing it.
Just one example plenty out there. Hey what carb and was it ever rebuilt?
https://www.ebay.com/itm/Car-Parts-Aluminum-Alloy-Check-Valve-Check-One-way-Gasoline-Diesel-Fuel-vcd/233209097062?_trkparms=ispr=1&hash=item364c586b66:g:ZbUAAOSwOz5cwnax&enc=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&checksum=2332090970621b719b47313740fbb9956ca7bab8f23d

 

[moparnation74]

Welcome to the new fuels......they dissipate......

You can pour some fuel in the carb prior to starting.....electric fuel pump or efi is the best fix.....

 

[493 Mike]

Have you tried a insulating base gasket? Choke rods are easy to fabricate longer versions of (1/8" gas welding wire is perfect).
Mike

 

[Dipstick]

Gas can't siphon from the bowl because there is an air gap between the bowl inlet and the fuel.

 

[Ratbastard]

Hence the term fuel bowl, there is only three ways out. Usage, evap., or boil. The fuel has to travel up at some point in a carb to get out. If you have no significant gasket leaks, but it could be leaking into the intake, for witch you would not see it. Electric pump was my choice, turn key. Wait ten seconds, fire motor.

 

[beanhead]

Yeah at shutdown, my levels are halfway up the sight glass like they should be. After sitting for a few hours or more the gas is always at the bottom, but the inlet is at the top of the bowl so it can't go anywhere but into the atmosphere. (It used to bubble on hot days but I've since added a spacer and some heat wrap where the fuel line runs near exhaust parts.) That said it still fires right up, sometimes needs a hit from the accelerator pump. It doesn't evaporate enough to go completely dry, and it be hot over here!

 

[Ratbastard]

Yeah at shutdown, my levels are halfway up the sight glass like they should be. After sitting for a few hours or more the gas is always at the bottom, but the inlet is at the top of the bowl so it can't go anywhere but into the atmosphere. (It used to bubble on hot days but I've since added a spacer and some heat wrap where the fuel line runs near exhaust parts.) That said it still fires right up, sometimes needs a hit from the accelerator pump. It doesn't evaporate enough to go completely dry, and it be hot over here!

Yea we’re here in so cal so we deal with a lot of heat. Which is why I did everything I could to cool the fuel and air that I could. Good luck with your mechanical adventures. We’re all here to help each other one way or another. Cruise cool bro

 

[Curiousyellow71]

Maybe your float is set lower then its suppose to be? Also maybe try a colder thermostat so she doesn't get as hot(do you know what temp thermostat you have now). Anything you can do to insulate the carb and fuel lines will help. A performance mechanical fuel pump will crank less and fill the carb up sooner.

 

[Cornpatch MO]

It’s probably percolating the fuel out of the carb into the intake. Try holding it to the floor to start it. Kim

Never flooded. I have to hit the starter for a few seconds, give time for fuel to get back to the bowl, hit the starter again and pump the pedal to activate the accelerator pump. I don't like to grind on the starter. ........MO

 

[Cornpatch MO]

Can also be the check valve in the fuel pump sorry man. I am sure there is a suitable check valve available but would really think about it before doing it.
Just one example plenty out there. Hey what carb and was it ever rebuilt?
https://www.ebay.com/itm/Car-Parts-Aluminum-Alloy-Check-Valve-Check-One-way-Gasoline-Diesel-Fuel-vcd/233209097062?_trkparms=ispr=1&hash=item364c586b66:g:ZbUAAOSwOz5cwnax&enc=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&checksum=2332090970621b719b47313740fbb9956ca7bab8f23d

Carb is clean and fairly recent rebuild. What you post here is what I had in mind. But you'uns have given me some things to consider........Thanks..............MO

 

[Cornpatch MO]

Have you tried a insulating base gasket? Choke rods are easy to fabricate longer versions of (1/8" gas welding wire is perfect).
Mike

It has a couple of thick base gaskets. Car starts easily until it sits for overnight.......................MO

 

[Cornpatch MO]

Gas can't siphon from the bowl because there is an air gap between the bowl inlet and the fuel.

shudda knowed---makes sense.............MO

 

[beanhead]

MO this is probably a dumb question but are you sure it's not some other issue like choke stuck open/not working?

 

[Cornpatch MO]

So the check valve in the fuel pump just assures constant pressure to the carb when the car is running? The pump looks fairly new...It was a real PITA to get the inside bolt started fighting the gasket sealer and the pump lever-spring and oil dipstick tube... I will check some of the suggestions and probably wind up with an inline , switched electric pump ...Thanks all............................MO

 

[toolmanmike]

The puppy pee gas we have Now days just plain evaporates! My 2 barrel 318 does it as does my AFB. I believe Artex makes a low pressure electric pump that can be hooked up with a momentary switch to prime the system.

 

[Cornpatch MO]

The puppy pee gas we have Now days just plain evaporates! My 2 barrel 318 does it as does my AFB. I believe Artex makes a low pressure electric pump that can be hooked up with a momentary switch to prime the system.

Does that mount in the line without needing a bracket? I assume the stock fuel pump will draw gas through the electric one when the power to it is shut off? I will see If I can find one..........Thanks............MO

 

[493 Mike]

Try a tank or two of recreational gas (no alcohol). That will confirm if it's the damn corn causing the problem. Just wait until they go to 15% corn squeezins!
Mike

 

[toolmanmike]

Try a tank or two of recreational gas (no alcohol). That will confirm if it's the damn corn causing the problem. Just wait until they go to 15% corn squeezins!
Mike

I am glad we have that here. 91 octane and not bad stuff but it still evaporates just not as fast.