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'77 Bronco owners - need help please

jkransbottom

Full Member
Joined
Jul 13, 2006
Messages
202
Loc.
Stallings, NC
Can someone with a '77 (or anyone who knows) please tell me where the connection in this picture is supposed to go to? Mine is disconnected at the other end and I don't know what it's for. A picture would be helpful and appreciated if possible. Thanks!

Carbtermination-1.jpg
 

ohpoo2

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Dec 21, 2005
Messages
873
Looks like it goes to the bottom of the pass. side exhaust manifold. some kind of heat source for carb. sorry no pics
 

Viperwolf1

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Aug 23, 2007
Messages
24,316
The exhaust manifold has a tube going through it. The top side of the tube is connected to the choke to heat it during engine warmup. The bottom side needs to let filtered air in to be heated.
 

Chief Master Sergeant

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Retired U.S. Air Force
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Nov 6, 2002
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5,172
The exhaust manifold has a tube going through it. The top side of the tube is connected to the choke to heat it during engine warmup. The bottom side needs to let filtered air in to be heated.

Doesn't that run to the choke on the side of the carb though? That's how my old carb was. There was a small tube at the bottom of the choke that this tube ran from to the passenger side exhaust manifold. Or, si that what I'm looking and just don't realize it?
 

Viperwolf1

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Doesn't that run to the choke on the side of the carb though? That's how my old carb was. There was a small tube at the bottom of the choke that this tube ran from to the passenger side exhaust manifold. Or, si that what I'm looking and just don't realize it?

Yep. Top side tube is exhaust manifold to choke. Bottom side tube is exhaust manifold to air cleaner/carb area where it picks up the filtered air.
 
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jkransbottom

jkransbottom

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Jul 13, 2006
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Loc.
Stallings, NC
OK, in this picture you can see the tube with the heat wrap that goes from the choke, across the back side/top of the passenger side valve cover and down connecting to the exhaust manifold. So the other tube coming from the back of the carb in my first picture should be going to the air cleaner, is that right? Where would it connect? Or does it need to go someplace else?

Tubewithheatwrap.jpg
 

Viperwolf1

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So the other tube coming from the back of the carb in my first picture should be going to the air cleaner, is that right? Where would it connect? Or does it need to go someplace else?

No. I'm saying the other end of it goes to the exhaust manifold. Where it's connected on the carb is fine to pickup clean air.
 
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jkransbottom

jkransbottom

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Joined
Jul 13, 2006
Messages
202
Loc.
Stallings, NC
Ahh (light going on), sorry. So both of these tubes should connect to the exhaust manifold. One goes to the choke and one to the carb via the connection in my first pic, correct? I don't know where the one from the carb will connect to the exhaust manifold but at least I know where to look now. Thanks.
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,875
If you look in the picture above it has both connections. One is the tube with the glass fiber wrap the other one is the rusty tube shown going under the back side of the carb. The 2 tubes meet at the end of the exhaust manifold on the top side. The rusty tube you see is the cold filtered air from the inside of the air filter which flows down the tube to the exhaust manifold for heat and then comes up the insulated side into the choke pulloff. There is a vacuum hole under that vacuum cover that causes the air to flow. Your Choke has both Vacuum activation and electrical shutoff and in your case it has a vacuum solinoid for full throttle choke pull off. There's alot going on with that choke function.
 

Steve83

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Jul 16, 2003
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Loc.
Memphis, TN, USA, Earth, Milky Way
Fresh air goes thru the filter, then down that hose to the bottom of the ex.man., up inside through a steel tube to pick up heat, then out thru another hose or tube to the choke where it helps heat the spring to UNchoke the carb.
 
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jkransbottom

jkransbottom

Full Member
Joined
Jul 13, 2006
Messages
202
Loc.
Stallings, NC
OK, thank you to all and for explaining how it works. That helps me a lot in being able to know what I'm looking for. I'll let you know what I find.
 
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