Return Fuel Line Restrictor

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WYSpider

Return Fuel Line Restrictor

Post by WYSpider »

For a return fuel hose in engine bay that has a 1-way valve installed do you put the restrictor before or after the 1-way valve? This is for a carbed car.

Return Fuel Hose Components in Engine Bay
Image
Last edited by WYSpider on Thu Aug 11, 2011 9:24 am, edited 1 time in total.
azygoustoyou

Re: Return Fuel Line Restrictor

Post by azygoustoyou »

Also if I can add to this, Where do you get the two way valve? I can't find it.
WYSpider

Re: Return Fuel Line Restrictor

Post by WYSpider »

Both pieces were inline after I had a Fiat mechanic install a DFEV 32/36 and relocate the electric fuel pump from the engine bay to the trunk.

Anyway I noticed the 1-way valve after I replaced the return fuel line in the engine bay. So I removed the valve from the old return hose. Then I noticed what looked like a splice in the old hose. When I took it apart I found the restrictor. Of course by that time I wasn't sure if the restrictor was set up before or after the 1-way valve. :?

The IDF Carb Tuning Guide has a discussion on restricting the return fuel line for electric fuel pumps.
http://fiatspider.com/f08/viewtopic.php?f=5&t=14494
Last edited by WYSpider on Thu Aug 11, 2011 11:48 am, edited 2 times in total.
baltobernie
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Re: Return Fuel Line Restrictor

Post by baltobernie »

azygoustoyou wrote:Also if I can add to this, Where do you get the two way valve? I can't find it.
This what you mean?

Image

They are NLA new or aftermarket; you'll have to find one from salvage. After bathing in gasoline vapor for forty years, they are incredibly brittle, and often disintegrate under the slightest stress. If you find one, gently cut the fuel lines off before removing from the car, then carefully slice off the old fuel line. The foam "intake" on the back will undoubtedly have to be replaced. You can use air filter material from a lawnmower.
donerehart
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Your car is a: 1976 spider

Re: Return Fuel Line Restrictor

Post by donerehart »

baltobernie wrote:
azygoustoyou wrote:Also if I can add to this, Where do you get the two way valve? I can't find it.
This what you mean?

Image

They are NLA new or aftermarket; you'll have to find one from salvage. After bathing in gasoline vapor for forty years, they are incredibly brittle, and often disintegrate under the slightest stress. If you find one, gently cut the fuel lines off before removing from the car, then carefully slice off the old fuel line. The foam "intake" on the back will undoubtedly have to be replaced. You can use air filter material from a lawnmower.
Are there any updated options to this plastic piece?
76 Spider
St. Louis, MO
BCTim
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Your car is a: 1976 Fiat 124 Spider

Re: Return Fuel Line Restrictor

Post by BCTim »

I'm also looking for a two-way valve (pressure relief valve?) and I was wondering if they are required?
If they are required, then why are they not available somewhere?
Mine is broken almost exactly as in the previous photo, tried glueing it but it broke when I put pressure on it.
Do we have any options for replacement?
1976 Fiat 124 Spider
2000 Subaru Impreza
2005 Subaru Outback (For skiing)
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bradartigue
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Re: Return Fuel Line Restrictor

Post by bradartigue »

Those fuel line components - especially that plastic one way valve - were recalled by FIAT an age or so ago. They crack, leak fuel, and are generally horrible. If you want a simple fuel return solution use a fuel filter with a return, available for around $6.00 from Auto Zone.

You should not need a one way valve with Webers; if you do then something is malfunctioning and fuel is being fed back to the tank.
baltobernie
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Re: Return Fuel Line Restrictor

Post by baltobernie »

This thread has disintegrated into two topics. The plastic valve I photographed is part of the vapor emissions control system. I'm not sure what the other item does.
donerehart
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Re: Return Fuel Line Restrictor

Post by donerehart »

donerehart wrote:
baltobernie wrote:
azygoustoyou wrote:Also if I can add to this, Where do you get the two way valve? I can't find it.
This what you mean?

Image

They are NLA new or aftermarket; you'll have to find one from salvage. After bathing in gasoline vapor for forty years, they are incredibly brittle, and often disintegrate under the slightest stress. If you find one, gently cut the fuel lines off before removing from the car, then carefully slice off the old fuel line. The foam "intake" on the back will undoubtedly have to be replaced. You can use air filter material from a lawnmower.
Are there any updated options to this plastic piece?
I'm still confused. Is this white plastic vapor separator needed now on a 76 with the 32/36 empi carb? Is there a substitute for it?
76 Spider
St. Louis, MO
majicwrench

Re: Return Fuel Line Restrictor

Post by majicwrench »

Who's on first??

Donerehart, does your car have one (white plastic vapor seperator) now?? Does car NEED it?? Well, if you are somewhere they check emission, methinks EVERYTHING has to be there, will anybody ever check?? Those that live in such place may be able to answer.
Does car need it to run?? No, unless it is the only vent source for the tank.

This thread started in 2011?? Who's raising the dead??
Keith
donerehart
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Your car is a: 1976 spider

Re: Return Fuel Line Restrictor

Post by donerehart »

majicwrench wrote:Who's on first??

Donerehart, does your car have one (white plastic vapor seperator) now?? Does car NEED it?? Well, if you are somewhere they check emission, methinks EVERYTHING has to be there, will anybody ever check?? Those that live in such place may be able to answer.
Does car need it to run?? No, unless it is the only vent source for the tank.

This thread started in 2011?? Who's raising the dead??
Keith
I just noticed that mine in the trunk was broken. I'm trying to determine if it is really needed. Not sure if my fuel return breather line really needs this plastic piece. No emission requirements in Missouri...thanks for asking clarifying questions.
76 Spider
St. Louis, MO
majicwrench

Re: Return Fuel Line Restrictor

Post by majicwrench »

Over the years I have "fixed" a lot of broken plastic valves simply by inserting/glueing another tube of sorts into broken tube. Like I said, my only concern about eliminating it is if it provides vent for the tank.
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