Strange Fuel Leak

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dreavis
Posts: 111
Joined: Wed Apr 08, 2015 2:32 am
Your car is a: 1977 Fiat 1800

Strange Fuel Leak

Post by dreavis »

Hi. My 1977 Spider has an interesting issue. After driving the car recently I put it in the garage. The next day my wife reported a strong fuel smell coming from the garage. I moved the car out of the garage and there was about 1/3 to 1/2 cup of gas in the drip pan I keep beneath the engine in case of oil drips. By the way, this has happened before, but then seemed to jave gone away. It has know happened twice in a row after driving the car.

My theory is that some pressure is built up in the carb/fuel lines and that pressure is slowly relieved to the point where there is not enough pressure to keep the fuel in the system and it then leaks out. I am taking the car to my guy tomorrow, but I was wondering if anyone else has experienced this and, if so, what was the cause and remedy.
I'm also interested in theories (not of the conspiracy variety) and thougths.

Thanks!
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Odoyle
Posts: 440
Joined: Mon Dec 01, 2014 10:06 pm
Your car is a: 1983 Pinafarina Spider
Location: CA

Re: Strange Fuel Leak

Post by Odoyle »

Could be the metal lines have corroded and there is a leak underneath where they run along the driver side.
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phaetn
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Posts: 575
Joined: Thu Jan 02, 2014 7:42 pm
Your car is a: 1974 Fiat Spider 1800
Location: Ottawa, ON Canada

Re: Strange Fuel Leak

Post by phaetn »

Can you tell if it's from the hard line, the rubber fuel line, or the carb itself?

I once had a fuel leak after taking off the carb to do some intake work and then reinstalling it. Turns out the floats in the bowl didn't actuate freely and so didn't press the pin to stop flow (because they didn't actually float but were stuck down/open). This eventually overflowed the bowl/chamber, saturated the gasket, then leaked out.

If you can, have a fire extinguisher with you. Fuel leaks around a hot engine can be a bad, bad thing.

Cheers,
phaetn
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baltobernie
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Posts: 3466
Joined: Sun Nov 25, 2007 6:00 pm
Your car is a: 1973 Spider [sold]
Location: Baltimore, MD

Re: Strange Fuel Leak

Post by baltobernie »

If you've retained the evap emissions system, a bad check valve could introduce extra pressure on the fuel system. I've seen fuel filler caps "pop" at the last few threads when removing. It's not hard to imagine a marginal fuel line or connection yielding under this condition.
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