Earls braided lines bleed fuel vapor?

[ULTM8Z]

So I'm putting my gas analyzer to use and am now able to truly pinpoint the source of that pesky fuel odor that I'm stuck with.

http://www.nastyz28.com/forum/showthread.php?t=69660

It's definitely the braided lines that I"m using for supply/return. All up and down the lines, when I put the sniffer to them, the HC's shoot up to 40-50 ppm compared to 0-2 ppm for normal air and around the rest of the engine compartment.

WHen I run the engine, I see absolutely no signs of liquid fuel leaking from anywhere along the fuel lines (and at 40 psi, any leak would be readily apparent). So what's the deal? Are the braided lines just porous enough to leak fuel vapors but not liquid fuel itself?

Has anyone heard of this phenomenon with braided lines? Do I need to switch to steel lines now?

[ULTM8Z]

Bingo...

http://www.ls1tech.com/forums/showthread.php?t=117014

http://www.chevelles.com/forums/show...d+line+fume s

I LOVE the internet...

Looks like I need to ditch this stuff and go for hard steel or something.

[Knuckle Dragger]

I'm living with the smell for now considering the cost to replace it all. Damn.

Good find, you know next time the car is at the shop I'm going to run the smog sniffer over the hose route.

[Skaal-tel 79]

wow that's crazy... you never hear about this kinda stuff from the magazines! God bless the internet.. and especially nastyz28

[ULTM8Z]

Hmmm... apparently this teflon-lined hose might do the trick.

http://www.earls.co.uk/earls/car/1_b...-flex_hose.pdf

[ULTM8Z]

Originally Posted by Knuckle Dragger

I'm living with the smell for now considering the cost to replace it all. Damn.

Good find, you know next time the car is at the shop I'm going to run the smog sniffer over the hose route.

Considering Mrs. ULTM8Z won't even go into the garage because it smells so bad (and always worries about me when I do), I don't think I'll have a problem selling this solution to her.

[Marks71BB]

Thanks for the heads up. Something to keep in mind when I get to building my fuel delivery system.

Mark

[Mr_Metal]

I'm happy that you've found and documented your fuel leak...

[Knuckle Dragger]

Originally Posted by ULTM8Z

Hmmm... apparently this teflon-lined hose might do the trick.

Do they use the same fittings as the braided line?

[Marks71BB]

of course not Dave... who are you kidding?? where would be the money in that?

[muscl car]

braided AN fuel line is nothing more than rubber fuel hose wrapped inside a metal braided jacket .so if they're leaking it's because the hose is old and brittle .the only other place i would think it would be leaking is from poor assembly of the fitting onto the hose . i've never heard of this before and have been around alot of race cars using braided line

[ULTM8Z]

Originally Posted by muscl car

braided AN fuel line is nothing more than rubber fuel hose wrapped inside a metal braided jacket .so if they're leaking it's because the hose is old and brittle .the only other place i would think it would be leaking is from poor assembly of the fitting onto the hose . i've never heard of this before and have been around alot of race cars using braided line

If it were a bad connection, the HC spike would be localized to that connection. But for the HC readings to be relatively constand along the entire length of BOTH supply and return lines indicates an apparent uniform degradation or a porosity that's susceptible to local fuel additives around here. My readings in conjunction with what I've just read on the internet have convinced me that the lines themselves are the culprit.

[ULTM8Z]

Originally Posted by Knuckle Dragger

Do they use the same fittings as the braided line?

Unfortunately, this "Speed-Flex" hose requires Speed-Flex fittings. Typical...

[Todd80Z28]

Have you ever thought about a career in semiconductor equipment troubleshooting? And, would you like to live in Northern VA?

Nice work! I would never have considered that.

[Ryan 79]

Would the problem exist with a carb and stock fuel pump?