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#57970 03/19/2006 2:52 AM | Joined: Mar 2006 Posts: 19 Junior Member | | Junior Member Joined: Mar 2006 Posts: 19 | i just purchased a 64 c20 with a 1970 chevy 350 engine. there is about 3/4 inch hose coming off the back of the carb not connected to anything. if i put my finger on the end of the hose the engine idle decreases and the engine wants to die. what the heck is this vacuum hose supposed to be connected to?
-anthony
"Send lawyers, guns, and money." W.Zevon
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#57971 03/19/2006 3:20 AM | Joined: Nov 2002 Posts: 1,002 Shop Shark | | Shop Shark Joined: Nov 2002 Posts: 1,002 | Some early PCV kits had a plate that mounted under the carb for the feed to burn the crank case fumes. Look for a PCV on a valve cover.
Larry
I don't own a vehicle that isn't old enough to drink.
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#57972 03/19/2006 3:32 AM | Joined: Mar 2006 Posts: 19 Junior Member | | Junior Member Joined: Mar 2006 Posts: 19 | thanks larry, but no pcv valve on the valve covers.
"Send lawyers, guns, and money." W.Zevon
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#57973 03/19/2006 3:58 AM | Joined: Nov 2005 Posts: 6,100 'Bolter | | 'Bolter Joined: Nov 2005 Posts: 6,100 | Hy ajc, That hose was probably connected to a brake booster at one time, if your not using it it should be plugged and the carb adjusted to run properly with it plugged, otherwise your engine is ingesting unfiltered air through that hose. | | |
#57974 03/19/2006 4:17 AM | Joined: Mar 2006 Posts: 19 Junior Member | | Junior Member Joined: Mar 2006 Posts: 19 | 3b, sorry but i'm a newbie at all this. how should the carb be adjusted if i plug it? would leaving it unplugged affect the way the truck runs. it seems to have a slight miss at above 30mph.
thanks,
-anthony
"Send lawyers, guns, and money." W.Zevon
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#57975 03/19/2006 5:10 PM | Joined: Jun 2004 Posts: 8,597 Riding in the Passing Lane | | Riding in the Passing Lane Joined: Jun 2004 Posts: 8,597 | You should have a pcv system. There must be a place on the valve cover for a pcv valve. If there is get a pcv valve for that engine & a piece of vacuum hose to conect it to the vacuum outlet. Adjust the idle speed screw to a normal idle speed & adjust the idle mixture screw clockwise till the engine slows down a little & back it out to smooth it out.
They say money can't buy happiness. It can buy old Chevy trucks though. Same thing. 1972 Chevy c10 Cheyenne SuperIn the Gallery Forum | | |
#57976 03/19/2006 5:43 PM | Joined: Mar 2006 Posts: 19 Junior Member | | Junior Member Joined: Mar 2006 Posts: 19 | Thanks for all the replies. I'll give the pcv valve a try today.
-anthony
"Send lawyers, guns, and money." W.Zevon
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#57977 03/19/2006 10:21 PM | Joined: Mar 2006 Posts: 19 Junior Member | | Junior Member Joined: Mar 2006 Posts: 19 | Wrenchbender, ok I plugged the vacuum hose and increaded the idle screw, idles fine now. Now there are two screws on the front of the carb, they seem to be set at the same position do I rotate both for the mixture?
thanks,
-anthony
"Send lawyers, guns, and money." W.Zevon
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#57978 03/20/2006 10:54 PM | Joined: Jun 2004 Posts: 8,597 Riding in the Passing Lane | | Riding in the Passing Lane Joined: Jun 2004 Posts: 8,597 | I don,t know why I was thinking 1 barrel. Yes the 2 screws down low on the carb are idle mixture screws. Adjust them as previously discribed.
They say money can't buy happiness. It can buy old Chevy trucks though. Same thing. 1972 Chevy c10 Cheyenne SuperIn the Gallery Forum | | |
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