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Topic: Fuel dripping

in Forum: C3 Fuel, Emission Control, and Exhaust Systems

Fuel dripping

Posted: 8/18/07 9:42am Message 1 of 7
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Simpsonville, SC - USA
Joined: 1/21/2007
Posts: 85
Vette(s): 1978 25th. Silver Anniversary Edition 350 L-82 Stock

 I’m having problems getting my 78 L-82 to idle at the correct RPM.  Sometimes I adjust the idle screw and get it at the correct RPM.  Then take it for a drive and notice the idle RPM has jumped up.  I started looking around and noticed fuel dripping off the ventures.  This is not supposed to happen at idle correct?  Sometimes the dripping stops and the engine will idle at a low RPM.  What would cause this?  Any help would be appreciated.




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Fuel dripping

Posted: 8/18/07 2:00pm Message 2 of 7
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Eastern Oklahoma County, OK - USA
Joined: 1/3/2006
Posts: 1560
Vette(s): 1980 Black L48 T-Tops
Can you give us a few more bits of info?

Type of Carb
Has Carb been rebuilt recently

That would help.



Fuel dripping

Posted: 8/19/07 5:19am Message 3 of 7
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Simpsonville, SC - USA
Joined: 1/21/2007
Posts: 85
Vette(s): 1978 25th. Silver Anniversary Edition 350 L-82 Stock
It's a Quadrajet 17059216 jetted to the original 17058211 specs.  Yes, it has been rebuilt recently. 


Fuel dripping

Posted: 8/19/07 2:16pm Message 4 of 7
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Canada
Joined: 8/6/2004
Posts: 533
Vette(s): Coupe 74 - 454 Drive it like you stole it!
Do you know where it's dripping from ?  A quick way to find out is with a match.Nuke
 
Seriously, last year, mine developed a gasoline smell.  It got so bad that I could barely walk into the garage; had to vent the garage 24/7 with giant fans and eventually had to park it outside.
 
Turns out it was the fuel pump that was dripping.
 
I gave you the long story, because some fuel problem will not smell all the time and some will; this could be an indicator of where the problem is.
 
Hope you find it quick; at 3$/gallon you don't wan't to waste that gold!



Fuel dripping

Posted: 8/20/07 9:15am Message 5 of 7
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Victor, NY - USA
Joined: 7/12/2004
Posts: 6841
Vette(s): 2004 Commemorative Edition Coupe, Auto w/HUD. 13K miles in 2015. Sold 1982 Red Coupe
"I started looking around and noticed fuel dripping off the ventures."
Do you mean the venturi, in the carb?



 
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Fuel dripping

Posted: 8/20/07 10:09am Message 6 of 7
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
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
If there is fuel dripping, or running out of either of the primary venturis with it idling, it is idling too high, or, as a long shot, the float level is too high.
The venturis need a vacuum signal to pull the fuel up out of the bowl, and down into the bore of the carb. There is really no other way for that to happen unless the throttle blades are open enough to expose the transfer slots that are located just above them.
Sounds like you are having to raise the idle speed to compensate for what is probably a too high float level(flooding). That's why the idle rpm gets higher after driving, as it is clearing out all of the raw fuel. Once it starts idling again, it loads up, and the idle goes down, and you have to raise it again to keep the engine running.
Looks like a carb build is in your future.


Joel Adams
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Fuel dripping

Posted: 8/21/07 9:07am Message 7 of 7
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Victor, NY - USA
Joined: 7/12/2004
Posts: 6841
Vette(s): 2004 Commemorative Edition Coupe, Auto w/HUD. 13K miles in 2015. Sold 1982 Red Coupe

If Joel is correct, and I'm betting he is, it sounds like whoever rebuilt the carb recently didn't get everything quite right.




 
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in Forum: C3 Fuel, Emission Control, and Exhaust Systems


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