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K
'79 L-48 / Original Q-Jet carb. (rebuilt) / Edelbrock Performer Intake
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Recently I have noticed a brownish colored stain on my intake manifold right up in the front between the carb. and the T-stat housing. It is not wet, just a bit dirty. It smells like gasoline.
I have looked above this area on the front of the carb. and have not found any disconnected lines or hoses. The fuel line is tight.
The motor seems to run fine / No fuel starving or such.
I'd like to straighten this out before it develops in to a bigger issue.
Any ideas?
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 22714
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
The carb is seeping fuel. Could be from the filter inlet, since it is in that area. You say the fuel line is tight, but is the fitting that the fuel line goes into also tight in the carb? There is a really thin nylon gasket that fits onto the end of the filter inlet, and that thing will seep if it is damaged, or loose. IT isn't enough of a leak to be visible, but it will seep out over time, and stain the intake like you describe.
It could also be a crack in the fuel bowl, but the fuel inlet seeping is more likely. I would suggest removing the filter inlet, and replacing that gasket on the end of it first. You can clean the intake, and get it dry, then place a paper towel under the inlet overnight, and see if there is any indication of seepage at that location.
Adams' Apple 2010-07-11 08:44:08
It could also be a crack in the fuel bowl, but the fuel inlet seeping is more likely. I would suggest removing the filter inlet, and replacing that gasket on the end of it first. You can clean the intake, and get it dry, then place a paper towel under the inlet overnight, and see if there is any indication of seepage at that location.
Joel Adams
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I hate "seepage"
ebo
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K
Joel,
I think we nailed it! The large nut on the portion of the carb. where the fuel line attaches was just a tad little bit loose. With the wrench on it was a small fraction of a turn, but some movement none the less. After that I started it up and let it run for 10 minutes. No leaks. After an hour of cool down, no leaks. I am letting it cool down for a few hours with a folded paper towel under the area in question.Can't say what could've caused that to become loose but it looks like I'm in the right place.
Kevin
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K
And as for you Mr. ebo man; 
Yeah, I guess I left it hangin' out there with words like seepage and brown stains. Now didn't I. 
'Figured you'd be lurkin' out there just waitin'.
Ah well, no diapers for me yet.
Yeah, I guess I left it hangin' out there with words like seepage and brown stains. Now didn't I.
'Figured you'd be lurkin' out there just waitin'.
Ah well, no diapers for me yet.
Hopefully a good running Vette and good health will allow me to catch up with you guys later this season.
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K
Well, it seems like this problem has reared its ugly head again.
After a 10 mile ride this morning I noticed the odor of gas fumes. After a look under the hood the same stain is present on the intake manifild and gasoline is definitely dripping out of the same location as before.
Again I put a 1" wrench on the large nut where the fuel line enters the (Q-Jet) carb. A very small turn of the wrench and the problem is solved........for now.
Any ideas on what I could do to keep this from reocurring?
Kevin
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Hey Kevin, do you know how to weld
Maybe some sealant on the threads? Not sure about that with the gas you need info from someone with more smarts about carbs than me. Good luck, hope to see you this fall.
Maybe some sealant on the threads? Not sure about that with the gas you need info from someone with more smarts about carbs than me. Good luck, hope to see you this fall.
Dave
Lifetime Member #116
Dave's '82 
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20111021145147r.jpg)
I'm thinking the fuel line may have a small split in it on the end. You will need to remove the line from the carb and examine it. A new line is not too hard to replace. DB
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 22714
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Gonna have to replace the gasket, IF it is leaking from the fitting going into the carb. Once tightened so far, the gasket will split. AS Dennis mentioned, the fuel line itself can develop a split, or the flare can be crushed enough to leak.
One trick to a temporary "fix" for the gasket is to run a couple rounds of sewing thread around behind it. You want to put the thread between the gasket, and the fitting, where it seats. This will make the gasket "thicker", basically, so it will seal. IF the gasket is actually split tho, this won't do any good, and will prolly make it worse.
My suggestion would be to remove the fitting, and replace the gasket. I don't know that you can get that gasket by itself...it does come in a carb O/H kit, tho...
(Tanx, Ken 
)
One trick to a temporary "fix" for the gasket is to run a couple rounds of sewing thread around behind it. You want to put the thread between the gasket, and the fitting, where it seats. This will make the gasket "thicker", basically, so it will seal. IF the gasket is actually split tho, this won't do any good, and will prolly make it worse.
My suggestion would be to remove the fitting, and replace the gasket. I don't know that you can get that gasket by itself...it does come in a carb O/H kit, tho...
(Tanx, Ken )Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
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K
Hey Fellers,
Thanks for the input on this.
I checked Auto Zone for just such a gasket with no success. The guy behind the counter might have been wingin' it. He told me the Edelbrock rebuild kit would have the gasket I need. I just was'nt sure he was right, so I held off. Maybe just a bad vibe, I dunno.
There are a few other local places I'll try for just the gasket. And I'll hope the fuel line is ok until I take it apart.
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in Forum: C3 HVAC, Fuel, Emissions, and Exhaust
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