Quadrajet Idle Mixing Screws

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.

custodian

Full Access Member
Joined
Apr 15, 2016
Posts
1,048
Reaction score
700
Location
Catawba
First Name
William
Truck Year
1973, 1985, 1986
Truck Model
C10, C30
Engine Size
5.3 LS, 350, 454
My idle mixing screws will not turn on my 86 C30 with a 454.
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
10,038
Reaction score
19,312
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
Is the carbureator on or off the car? Off the car, clean and dry I'd try hitting it with propane. On the car I'd use a soldering iron to apply heat use patience and more heat you know mixture screws only effect idle mixture. So push comes to shove leave them alone. Let it be rich at idle.
 

75gmck25

Full Access Member
Joined
Oct 13, 2016
Posts
2,766
Reaction score
3,067
Location
Northern Virginia
First Name
Bruce
Truck Year
1975
Truck Model
K25 Camper Special TH350 NP203
Engine Size
5.7
Are you sure the anti-tamper plugs that cover the idle mixture screws have been removed? I believe there is a special drill bit that is designed to drill out the plugs, but mine had already been done before I bought the carburetor at a pick and pull.
 

custodian

Full Access Member
Joined
Apr 15, 2016
Posts
1,048
Reaction score
700
Location
Catawba
First Name
William
Truck Year
1973, 1985, 1986
Truck Model
C10, C30
Engine Size
5.3 LS, 350, 454
Are you sure the anti-tamper plugs that cover the idle mixture screws have been removed? I believe there is a special drill bit that is designed to drill out the plugs, but mine had already been done before I bought the carburetor at a pick and pull.
I took the carb loose and sprayed them with PB Blaster. They turn now.
 

Latest posts

Forum statistics

Threads
48,501
Posts
1,069,519
Members
42,960
Latest member
Ed Stewart
Top