Carb help
Thread Starter
|
Freshman User
Joined: Sep 2010
Posts: 37
Likes: 0
Carb help
Hi,
Truck is a '73 F350 SCS w/ 390 engine. We ran in to a big problem last year where the truck back fired and bent several of the push rods which causes 2 of the lifters to pop out of place. Intake, carb, distributor, etc all had to be removed to fix.
Anyway, to make a long story short I need some help with one of the vacuum lines on the carb. I'll attach a picture and the piece in question is circled in red. What is this for? I cannot remember if this was connected before or not but now it's causing a huge vacuum leak. There is nothing on the air breather that attaches here either. The air breather on the truck is the one that you put oil in it. There is nothing on the bottom of it that goes in to this hole so the hole is wide open.
Truck is a '73 F350 SCS w/ 390 engine. We ran in to a big problem last year where the truck back fired and bent several of the push rods which causes 2 of the lifters to pop out of place. Intake, carb, distributor, etc all had to be removed to fix.
Anyway, to make a long story short I need some help with one of the vacuum lines on the carb. I'll attach a picture and the piece in question is circled in red. What is this for? I cannot remember if this was connected before or not but now it's causing a huge vacuum leak. There is nothing on the air breather that attaches here either. The air breather on the truck is the one that you put oil in it. There is nothing on the bottom of it that goes in to this hole so the hole is wide open.
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
That's the fresh-air intake for the hot-air choke. It literally goes straight to the nipple underneath that you have plugged off. Therefore it is not causing any sort of vacuum leak and your problem is elsewhere.
Please refer to the following explanation of what that port does with regard to the hot-air choke: https://www.ford-trucks.com/forums/8...ml#post6939116
Please refer to the following explanation of what that port does with regard to the hot-air choke: https://www.ford-trucks.com/forums/8...ml#post6939116
Thread Starter
|
Freshman User
Joined: Sep 2010
Posts: 37
Likes: 0
I did put a vacuum line on that nipple. The line goes to a brass T thing on the intake near the pass side valve cover. After reading your post I'm thinking that line shouldn't go there. I'll have to see if I can find another spot for it. I'm not the one who took these lines off so I am not sure where they go.
Thanks for the link. That helps me understand
Thanks for the link. That helps me understand
Thread Starter
|
Freshman User
Joined: Sep 2010
Posts: 37
Likes: 0
I got it figured out though. Nothing is supposed to go on that nipple. There are after market headers on the truck and the fresh air intake part isn't there. There's just the hot air tube and it hangs down by the header.
The vacuum hose I had on the nipple on the carb was actually supposed to go on this metal tube near the firewall.
Thread
Thread Starter
Forum
Replies
Last Post
lyndonff
Fuel Injection, Carburetion & Fuel System
8
Dec 1, 2020 03:07 PM
WhoaFiveOh
1973 - 1979 F-100 & Larger F-Series Trucks
10
Aug 18, 2013 04:41 PM
lvin4jc
1961 - 1966 F-100 & Larger F-Series Trucks
12
Aug 20, 2011 02:49 AM
WPlayer
1973 - 1979 F-100 & Larger F-Series Trucks
105
Jan 5, 2011 11:56 PM
