Can someone tell me what this round thing is with a vacuum line pointing up? On a 1984 ford F150 302.
What is this part on my carburetor?
- Thread starter mpack88
- Start date
Check valve?
Looks like a vent from the fuel tank in a closed vented system.
OVERKILL
$100 Site Donor 2021
This. Looks like a check valve.
Its tied into the egr and purge solinoid.
AutoMechanic
Site Donor 2024
Check valve
This ^. The plastic part in the line is a vacuum delay valve.
I should have been more clear. Yes, the metal disk is a check valve and the pastic disk is a vacuum delay valve. 
Ok, found out it's a temperature compensating valve that regulates the power valve. Reduces fuel shot when engine is hot. Thanks for the replys.
Carbs got too complicated right before fuel injection got popular!
Agree. I think I'll purchase a Holly 2300 2brrl. None of its emissions stuff is working anyway.
Fuel shot?
Amount of fuel the power valve allows when vacuum drops.
Its an old styled inline doohickey
Sounds complicated and borderline convoluted.
Also seems like the kind of thing a computer controlled fueling system could handle much better.
I think I will set about inventing just such a system. Y’all better get ready to be impressed, this is gonna revolutionize the automotive industry!
Thingamajig
Are you sure about that? Where does the other end of the hose go to?
kind of like a duty cycle solenoid an electronic carburetor.
To a tempurature switch then to intake manifold vacuum
