73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: ole blue on September 04, 2008, 06:05:49 pm
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I just bought a 79 seirra grande with a 350 and quadrajet, truck runs great but gets horrible mileage. I cleaned the air filter(k&n) and while it was off I noticed that a larger vacuum outlet(?) at the front of the carb near the top was not connected to anything. I could not find a unconnected vacuum hose anywhere. My question is is supposed to capped off or conected somewhere else.
Thanks
Rod
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Pretty sure you are looking at the vent tube that would go to the charcoal canister.
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On mine it goes to the PCV valve and the charcoal cannister
(http://i123.photobucket.com/albums/o317/jjsabol/scan0001.jpg)
(http://i123.photobucket.com/albums/o317/jjsabol/IM0010871.jpg)
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So it looks like is should go to the pcv valve. Thanks im gonna check it out... Will it hurt to not go to anything?
Rod
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i have a q-jet as well. Id say defn hook up your pcv valve should make it run better id think. and if you dont want to hook it up, which i dont reccomend, at leawst plug it off cause your carb will be sucking in un filtered air which is not good. and also put a breather cap where your pcv should be. but again i would just hook it up. hope it helps
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I would recommend hooking up the PVC valve also. At a minimum, you need to do as jefferias suggests if you don't use the PVC valve.
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You NEED a PCV valve or it will find any weak spot and blow all the oil out of it. If you are running a breather on the valve cover, you should be ok.