Gas smell???

[Jeffs Black 97 Formula A4]

Not sure if this is normal, but I was working under the hood and happened to have my nose near the three gas lines coming out of the driver side shock tower, and the lines smelled like gas (though I had to be really close to them to smell the gas). Is this normal (since obviously gas flows through them)? Or do I have a problem? Car runs great. Thanks!

EDIT: The smell was more apparent toward the plastic tube that holds the lines in place (near the air filter box). Are these lines fragile? I did not see or notice any liquid.

[Injuneer]

There are three lines in the bundle. One is the fuel supply and one is the fuel return. Both those run to the back of the intake manifold and connect to the fuel rails. The third line, which drops off to a metal U-shaped tube midway down the intake manifold is the vapor vent/purge line from the charcoal EVAP canister in the driver's rear fender.

The lines are fairly rugged, although there were some reports in early years of the clip that holds them to the throttle linkage cover breaking, and dropping them in the exhaust manifolds, where they melted and started a fire. Haven't heard of that happening much.

If it was a leak in the fuel supply or return lines, there would be a flow of liquid, since the system operates at about 45psi. If there was a hole in the vapor line from the EVAP canister, there would be a fuel smell but no liquid.

Since the lines are plastic, perhaps there's enough molecular permeation to produce a fuel odor, even though there isn't a leak. I'd take the time to examine the lines and insure there is no liquid present, or that the vapor line isn't cracked.

[Jeffs Black 97 Formula A4]

I was sniffing around some more and noticed some fuel odor near the driver side fender as well. What does this mean? I had the car out earlier tonight and it ran great, and there is no SES light. I also checked under the hood and there is definitely no gas leak to be found anywhere. What does this mean if I can smell some fuel vapor as I get closer to the driver fender?

If this is a problem, how would I inspect the fuel system? Thanks

[Injuneer]

The charcoal canister may be saturated. The rubber lines that connect it to the top of the fuel tank may be rotted (most common problem). The fuel cap seal could be faulty.

Diagram courtesy of Shoebox:

http://shbox.com/1/evap_system.jpg

[Jeffs Black 97 Formula A4]

I actually smelled fuel vapors at the front of the car, nothing at the rear. Is that still an indication of the canister issue? I can probably eliminate the gas cap seal being the problem since I have no SES light, and when I open the cap it does allow vapors to escape.

[Injuneer]

Sorry... when you mentioned driver side fender, I mistakenly assumed you had gone to the back where the canister is located.

No, an odor in the front will not be from the canister. The fuel hard lines end right under the floor, near the front edge of the drivers door. From there, up through the inner fender and on to the fuel rails, they are plastic. Might be worth looknig at the ends of the plastic lines under the car, and pulling the plastic inner fender liner to look at the lines.

[Jeffs Black 97 Formula A4]

No leaks anywhere. Also, the car is garage kept and there is no fuel smell in the garage.

[Jeffs Black 97 Formula A4]

No leaks anywhere. Also, the car is garage kept and there is no fuel smell in the garage.

Based on my findings, do I have a problem or is it normal on LT1 cars?

[Jeffs Black 97 Formula A4]

Even though the dealer said there is no problem here, I still have my doubts. See the picture, the arrow points to where I smell some gas. I don't smell anywhere on the plastic tube that holds all three lines except at the opening near the fuse box. Anyone else with an LT1 able to help me? I still don't have a SES light, and the car still runs fantastic with no sputtering, stalling, or hesitation, even at WOT. Thanks!

Click here to see what I'm talking about.

[97LT1Z28]

It is possible, since the lines are surrounded by a tube, that you could have some vapor leaking out at the connections on the fuel rail - upstream, and the vapor is finding it's way out at the end of the tube.

Has anyone ever disconnected the fuel supply lines to do any work to the fuel system?

[Jeffs Black 97 Formula A4]

I never had any work done to the fuel system. And I never saw any liquid coming out of the tube, or anywhere else. I only smell at the opening. If I sniff around other places on that tube, I don't smell it.

There was a piece of masking tape around the opening, I wonder if it was supposed to block the odor?