Carb and vacuum line problems

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
11,254
Reaction score
17,185
Location
Right where I am
First Name
Bagoomba
Truck Year
1981
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s
Engine Size
Carb'ed Vortec 350
I appreciate the advice. I will be getting some vacuum hose and going to work on my truck this weekend. I do have a question though. What is the metal flexible duct that goes up from my left valve cover to my air cleaner? It doesn't fit on there very tightly, do I have to worry about that leaking?

That's to draw warm air in the carburetor when the engine is cold. It's loose by design, leave it on there.
 

Goldie Driver

Full Access Member
Joined
Mar 19, 2018
Posts
4,042
Reaction score
6,634
Location
Houston, Texas
First Name
Britt
Truck Year
1980
Truck Model
GMC K1500 Suburban
Engine Size
350
This one any better?

You must be registered for see images attach
 

Ewhitaker0020

Full Access Member
Joined
Apr 21, 2019
Posts
272
Reaction score
92
Location
Kentucky
First Name
Eric
Truck Year
1984
Truck Model
K10
Engine Size
305 5.0
This one any better?

You must be registered for see images attach

Yep. It looks to me like I'm missing the linkage between the back vacuum thing and the secondary air flaps. I know my terminology stinks lol. That answered my question perfectly, thank you. Now I have to figure out how to find one. Do you know what that linkage does?
 

Goldie Driver

Full Access Member
Joined
Mar 19, 2018
Posts
4,042
Reaction score
6,634
Location
Houston, Texas
First Name
Britt
Truck Year
1980
Truck Model
GMC K1500 Suburban
Engine Size
350
Yep. It looks to me like I'm missing the linkage between the back vacuum thing and the secondary air flaps. I know my terminology stinks lol. That answered my question perfectly, thank you. Now I have to figure out how to find one. Do you know what that linkage does?

I am no carb expert, but there are some on here !:cool:

I thought it was a part of the choke ...
 

Ewhitaker0020

Full Access Member
Joined
Apr 21, 2019
Posts
272
Reaction score
92
Location
Kentucky
First Name
Eric
Truck Year
1984
Truck Model
K10
Engine Size
305 5.0
I am no carb expert, but there are some on here !:cool:

I thought it was a part of the choke ...

It might be part of the choke. Hopefully I can find one. I could probably make my own but I wouldn't know if it was right or not.
 

Johnathan S

Junior Member
Joined
Apr 11, 2019
Posts
28
Reaction score
11
Location
Fort Worth, TX
First Name
Johnathan
Truck Year
1986
Truck Model
C10
Engine Size
350
Yes this is how my truck looked when I got it, the original 305 and Rochester carb spaghetti lines everywhere. Over time I gradually figured out what lines I could take off and what ones I couldn’t for the engine to run ok. All my smog equipment like pump and charcoal canister I yanked out. Here in Texas if it’s over 25 years old you don’t have to get emissions checked or safety checked. I’d get an EGR block off plate for the manifold those tend to stick open and leak. The only vaccum lines you need are for the distributor advance, the A/C which should be connected to the manifold vaccum port behind the carb, PCV and cruise control, and slide power brakes which should be connected by a hardline to the back of the carb it oh and the TC Lockup if your transmission has one. Everything else you can block off with rubber vaccum caps. Honestly I’d just get a cheap Edelbrock 1406 those are easier to deal with vaccum wise. ALSO if you have stock exhaust manifolds which it looks like you do, the passenger side one has a vaccum operated valve that’s used for cold starts of make sure that doesn’t stick close
 
Last edited:

Ewhitaker0020

Full Access Member
Joined
Apr 21, 2019
Posts
272
Reaction score
92
Location
Kentucky
First Name
Eric
Truck Year
1984
Truck Model
K10
Engine Size
305 5.0
Yes this is how my truck looked when I got it, the original 305 and Rochester carb spaghetti lines everywhere. Over time I gradually figured out what lines I could take off and what ones I couldn’t for the engine to run ok. All my smog equipment like pump and charcoal canister I yanked out. Here in Texas if it’s over 25 years old you don’t have to get emissions checked or safety checked. I’d get an EGR block off plate for the manifold those tend to stick open and leak. The only vaccum lines you need are for the distributor advance, the A/C which should be connected to the manifold vaccum port behind the carb, PCV and cruise control, and slide power brakes which should be connected by a hardline to the back of the carb it oh and the TC Lockup if your transmission has one. Everything else you can block off with rubber vaccum caps. Honestly I’d just get a cheap Edelbrock 1406 those are easier to deal with vaccum wise. ALSO if you have stock exhaust manifolds which it looks like you do, the passenger side one has a vaccum operated valve that’s used for cold starts of make sure that doesn’t stick close

My EFE on the exhaust manifold isn't hooked up right now. Actually it has mud in the vacuum port. Does it being unhooked mean it's stuck closed or open? Somebody in another forum said it looks like my carb gaskets have been cooked because of that system running hot exhaust past my carb all the time.
 

Ewhitaker0020

Full Access Member
Joined
Apr 21, 2019
Posts
272
Reaction score
92
Location
Kentucky
First Name
Eric
Truck Year
1984
Truck Model
K10
Engine Size
305 5.0
I am no carb expert, but there are some on here !:cool:

I thought it was a part of the choke ...

Hey, turns out I can buy that part. The website I ordered my rebuild kit from sells the linkage. They call it a choke pull off link.
 

gotyourgoat

Full Access Member
Joined
Mar 27, 2014
Posts
2,117
Reaction score
3,418
Location
NRV Virginia
First Name
gotyourgoat
Truck Year
1984
Truck Model
c10
Engine Size
smokin' 305
Yes this is how my truck looked when I got it, the original 305 and Rochester carb spaghetti lines everywhere. Over time I gradually figured out what lines I could take off and what ones I couldn’t for the engine to run ok. All my smog equipment like pump and charcoal canister I yanked out. Here in Texas if it’s over 25 years old you don’t have to get emissions checked or safety checked. I’d get an EGR block off plate for the manifold those tend to stick open and leak. The only vaccum lines you need are for the distributor advance, the A/C which should be connected to the manifold vaccum port behind the carb, PCV and cruise control, and slide power brakes which should be connected by a hardline to the back of the carb it oh and the TC Lockup if your transmission has one. Everything else you can block off with rubber vaccum caps. Honestly I’d just get a cheap Edelbrock 1406 those are easier to deal with vaccum wise. ALSO if you have stock exhaust manifolds which it looks like you do, the passenger side one has a vaccum operated valve that’s used for cold starts of make sure that doesn’t stick close
Just because you can yank all those things out doesn't mean you should. When this guy is back here in a few months saying he smells gas from under the hood and there's gas leaking out of the filler neck he's gonna wish there was less yanking to undo. Keep the charcoal can and the pcv, they work together.

Your year and engine are the same as mine but I'm not sure our carbs are the same, I don't have that larger vacuum thingie, whatever it's called, on the passenger side.
Mine is 17083224 I was forced to buy a rebuilt one because the previous owner relieved me of so damn many parts off the original I had a rebuilder literally laugh at me and tell me it's nothing but a core at best. :banghead: More than happy to snap a pic of how this carb should look if you want.
 

Ewhitaker0020

Full Access Member
Joined
Apr 21, 2019
Posts
272
Reaction score
92
Location
Kentucky
First Name
Eric
Truck Year
1984
Truck Model
K10
Engine Size
305 5.0
Just because you can yank all those things out doesn't mean you should. When this guy is back here in a few months saying he smells gas from under the hood and there's gas leaking out of the filler neck he's gonna wish there was less yanking to undo. Keep the charcoal can and the pcv, they work together.

Your year and engine are the same as mine but I'm not sure our carbs are the same, I don't have that larger vacuum thingie, whatever it's called, on the passenger side.
Mine is 17083224 I was forced to buy a rebuilt one because the previous owner relieved me of so damn many parts off the original I had a rebuilder literally laugh at me and tell me it's nothing but a core at best. :banghead: More than happy to snap a pic of how this carb should look if you want.
I would appreciate you snapping some pictures for me. I will be keeping the canister and the pcv valve, in fact I just ordered a new one in case mine is plugged up since it was only a couple of dollars. More than anything I want to eliminate the air system. It's huge and hides so much of my engine. Plus, the air pump isn't even hooked up anymore.

My carb number is 17080206

Sent from my ONEPLUS A3000 using Tapatalk
 

Johnathan S

Junior Member
Joined
Apr 11, 2019
Posts
28
Reaction score
11
Location
Fort Worth, TX
First Name
Johnathan
Truck Year
1986
Truck Model
C10
Engine Size
350
My EFE on the exhaust manifold isn't hooked up right now. Actually it has mud in the vacuum port. Does it being unhooked mean it's stuck closed or open? Somebody in another forum said it looks like my carb gaskets have been cooked because of that system running hot exhaust past my carb all the time.
Yep that’s form the EGR valve on the intake, it really does nothing and it probably doesn’t work, as far as the valve on the manifold it should be open without vaccum, if you want to you can undo the linkage from the valve and try and free it up with some WD-40
 

Johnathan S

Junior Member
Joined
Apr 11, 2019
Posts
28
Reaction score
11
Location
Fort Worth, TX
First Name
Johnathan
Truck Year
1986
Truck Model
C10
Engine Size
350
Just because you can yank all those things out doesn't mean you should. When this guy is back here in a few months saying he smells gas from under the hood and there's gas leaking out of the filler neck he's gonna wish there was less yanking to undo. Keep the charcoal can and the pcv, they work together.

Your year and engine are the same as mine but I'm not sure our carbs are the same, I don't have that larger vacuum thingie, whatever it's called, on the passenger side.
Mine is 17083224 I was forced to buy a rebuilt one because the previous owner relieved me of so damn many parts off the original I had a rebuilder literally laugh at me and tell me it's nothing but a core at best. :banghead: More than happy to snap a pic of how this carb should look if you want.
No I understand if you want to keep it all you can but the motor doesn’t need any of it to run right. And if you keep it in and experience problems it’s just harder to trace. By all means keep it all I just had a lot of people tell me to take it all out and it worked for me
 

spanky55amg

I'll give u $5, a hardy handshake, & 5 fish sticks
Joined
Jun 6, 2017
Posts
819
Reaction score
212
Location
Dallas, TX
First Name
Spanky
Truck Year
1984
Truck Model
C10 Short Fleet
Engine Size
V8
Just an FYI. I run a Q-jet and have ZERO emissions.

The vacuum advance, HVAC, choke, PCV, and TCC switch are all that I have hooked up to the carb.
 

gotyourgoat

Full Access Member
Joined
Mar 27, 2014
Posts
2,117
Reaction score
3,418
Location
NRV Virginia
First Name
gotyourgoat
Truck Year
1984
Truck Model
c10
Engine Size
smokin' 305
No I understand if you want to keep it all you can but the motor doesn’t need any of it to run right. And if you keep it in and experience problems it’s just harder to trace. By all means keep it all I just had a lot of people tell me to take it all out and it worked for me

I'm not saying a gen 1 small block won't run without a bunch of bits and bobs attached. They do. They'll run on liquid soap for Christ sake. Now longevity is probably a coin toss with the soap but there's a thousand ways to skin a cat.

The canister actually has a relatively simple purpose rooted in science in the fact that volatile fluids like gasoline expand and contract quite a bit from just a small difference in things like temp and air pressure. This is where the canister comes in. One line to the canister is from the gas tank so if you remove the charcoal can you still have to find a way to cap that line and you will need to source a gas cap that vents to the atmosphe at minimum. Just seems easier and possibly less mess to have a canister. Think of it like less of a smog item and more of a hey I don't have to deal with cleaning up leaking or spilled gas with this relatively unseen cylinder and it functions with my two outlet pcv so all is fine can.

Just an FYI. I run a Q-jet and have ZERO emissions.

The vacuum advance, HVAC, choke, PCV, and TCC switch are all that I have hooked up to the carb.

The same q-jet? Hell, you have a fancy optioned truck.
 
Last edited:

Forum statistics

Threads
44,168
Posts
950,807
Members
36,286
Latest member
goodwrenchca
Top