Fuel line dries out

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tonyvtx
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Joined: Sun Apr 28, 2019 6:14 am

Fuel line dries out

Post by tonyvtx »

Hi all,

The car is on a driveway with a slight incline with the front of the car higher than the rear. The car is not yet completed but it is noted that since she was last started, the fuel line is dry, including the filter glass. I suspect that the fuel has drained back to the tank and now, possibly the pump needs priming. Is there a non-return valve in the fuel line that would normally prevent this drain-back?

Any help and suggestions would be appreciated. Thanks.

Tony
jtschug
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Re: Fuel line dries out

Post by jtschug »

The fuel pump is a diaphragm type that does not need priming.
1966 Thunderbird Convertible (Emberglo / White-Emberglo)
Modified 428 - stroked, rollercam, aluminum top end, headers
Livermore, CA
tonyvtx
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Re: Fuel line dries out

Post by tonyvtx »

Hi,

OK thanks for that.

I'm still wondering about the non-return arrangement. You can't have the fuel draining back to the tank every time you park on a hill....

Tony
Terry64HT
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Re: Fuel line dries out

Post by Terry64HT »

The fuel line is steel, but has a short section of rubber behind the driver's side inner fender. This rubber makes the turn from horizontal (along the underside of the car) to vertical (up the firewall). Over the years this rubber deteriorates and will begin to leak, often not enough to cause a gas puddle on the floor. It will collect on the inside of the inner fender and evaporate. There is usually a gas smell as well that people usually attribute to carb problems.
It's a cheap fix, but means removing the wheel and then inner fender. A couple of hours work.
Hope this helps
Terry
64HT
jtschug
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Re: Fuel line dries out

Post by jtschug »

gasoline could be boiling during a hot soak and building up pressure to push the liquid back into the tank
1966 Thunderbird Convertible (Emberglo / White-Emberglo)
Modified 428 - stroked, rollercam, aluminum top end, headers
Livermore, CA
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RedBird64
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Re: Fuel line dries out

Post by RedBird64 »

There's no check valve in the lines.
What I noticed when taking the line loose that feeds the pump is that there's a syphon effect in action. So no check valve is needed.
Our modern corn-gas dries up very easiily though and that could be a contributing factor.

Scott
Last edited by RedBird64 on Wed May 22, 2019 11:10 am, edited 1 time in total.
1964 Coupe Wimbledon white/Rangoon Red w/black int. Owned for 42 years. It was my folks car before that (second owners). VTCI # 12013.
scumdog
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Re: Fuel line dries out

Post by scumdog »

tonyvtx wrote: Tue May 21, 2019 8:42 am Hi,

OK thanks for that.

I'm still wondering about the non-return arrangement. You can't have the fuel draining back to the tank every time you park on a hill....

Tony
There would still be enough fuel in the carb to get the motor running - and that’s enough to get fuel pumped up from the tank.
My ‘bird has a dry line after sitting for a week or two.
It takes some cranking until fuel gets pumped up to the carb - so normally I pour half an egg-cup of fuel down the carb then twist the key.
By the time that fuel has been used up there is fuel in the carb. (Sometimes it takes a second bit of fuel down the carb to get the fuel to the pump)

But day to day use or even after five or six days the car starts right up without the fuel-down-the-carb trick.
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tbird
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Re: Fuel line dries out

Post by tbird »

The fuel pump has a check valve built into it>
Jim Mills
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tonyvtx
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Re: Fuel line dries out

Post by tonyvtx »

Thank you everybody.

It is true that she hasn't run for a few weeks so maybe an agg cup or teo in the carb is the answer.

However there are conflicting comments. Scott says that there is no check valve in the system and tbird says there is one built in to the pump itself... ???

Are there any more views please?

Tony
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redstangbob
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Re: Fuel line dries out

Post by redstangbob »

actually the fuel pump has 2 check valves and a diaphragm. I suspect after 2 weeks of sitting evaporation is the problem. I go through the same with my own car. Todays replacement fuel pumps aren't too swift, I wouldn't be surprised if the check valves seeped a bit over time. JMO Bob C
It's gonna be cool when it's done
And now it's really cool !!



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tonyvtx
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Re: Fuel line dries out

Post by tonyvtx »

Thanks Bob.

Tony
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sseebart
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Re: Fuel line dries out

Post by sseebart »

scumdog wrote: Tue May 21, 2019 9:30 pm It takes some cranking until fuel gets pumped up to the carb - so normally I pour half an egg-cup of fuel down the carb then twist the key.
By the time that fuel has been used up there is fuel in the carb. (Sometimes it takes a second bit of fuel down the carb to get the fuel to the pump)

But day to day use or even after five or six days the car starts right up without the fuel-down-the-carb trick.
I do the same, except that I use commercially available starting fluid that comes in spray cans. I dislike handling raw gas before hopping into the car.

~Steve
tonyvtx
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Re: Fuel line dries out

Post by tonyvtx »

I can understand that Steve.

Tony
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