Help! Missing vac Tubes?
Thread Starter
Intermediate
Joined: Jun 2010
Posts: 47
Likes: 0
From: Chicago IL
Help! Missing vac Tubes?
Guys
I'm a new owner of 81 Corvette, Don't know much about old cars, Need your help
I removed air filter pan and found out that there is a long screw inserted in a tube in a back of carburetor. Do you know what that would be? why it is there? should it be connected somewhere? 1st pic
Also there is a 4 way connector that goes to air filter pan, one side goes to the pan, another side goes to air tube, and there are two pins that are open, shouldn't they be connected to something? Please take a look at 2nd pic, ( the red plastic piece)
I'm a new owner of 81 Corvette, Don't know much about old cars, Need your help
I removed air filter pan and found out that there is a long screw inserted in a tube in a back of carburetor. Do you know what that would be? why it is there? should it be connected somewhere? 1st pic
Also there is a 4 way connector that goes to air filter pan, one side goes to the pan, another side goes to air tube, and there are two pins that are open, shouldn't they be connected to something? Please take a look at 2nd pic, ( the red plastic piece)
Melting Slicks
Joined: May 2003
Posts: 2,076
Likes: 281
From: Dyersburg TN
looks like someone has started removing the polution controls. There are valves in the air intakes that cause the car to pull hot air off the manifolds to help the car warm up when it is cold. You should get a shop manual to get info on how to hook up the hoses of you want them repaired.
Tech Contributor
Joined: Aug 1999
Posts: 14,374
Likes: 6,373
From: At my Bar drinking and wrenching in Lafayette Colorado
The pugged tube is the manifold vacuum source for the air cleaner hot air flapper door operation and controls. The "T" connection on the air cleaner is also part of this system. Someone has removed and disabled this system to prevent the air cleaner doors from closing and providing warm air to the carb under cold outside air conditions.
Lars
Lars
Racer
Joined: Feb 2007
Posts: 290
Likes: 0
From: Winchester CA
One of the connectors on the red thermal vacuum switch connects to the EFE valve that is located on the base of the passenger side exhaust header. It is connected via a hard pre-bent tube that also has a hose hooked to it.
Acct suspended by request 19 April 2011
Joined: Jul 2009
Posts: 478
Likes: 0
From: La Porte In
http://earchitect.50megs.com/corvett...s/eng-vacc.jpg
This is a schematic of the L82. I believe the L81 to be the same.
Gary
This is a schematic of the L82. I believe the L81 to be the same.
Gary
Le Mans Master
Joined: Nov 1999
Posts: 5,768
Likes: 3
From: San Diego CA
http://earchitect.50megs.com/corvett...s/eng-vacc.jpg
This is a schematic of the L82. I believe the L81 to be the same.
Gary
This is a schematic of the L82. I believe the L81 to be the same.
Gary
The schematic is for the 78 so no warantees on how applicable it is to the 81
Acct suspended by request 19 April 2011
Joined: Jul 2009
Posts: 478
Likes: 0
From: La Porte In
81 is shown the same as 78 in the Chilton book. Different bore and different compression than the l82.
http://www.motorera.com/corvette/index.htm
http://www.motorera.com/corvette/index.htm
Tech Contributor
Joined: Aug 1999
Posts: 14,374
Likes: 6,373
From: At my Bar drinking and wrenching in Lafayette Colorado
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
