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ASEMaster35yrs, Chevy Technician
Category: Chevy
Satisfied Customers: 2095
Experience:  ASE Certified since 1972,Master Auto tech,Heavy Truck Tech ,chev dealer tech
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rochester quadrajet carburetor on a 1979 chevy

Resolved Question:

Need help with Rochester quadrajet carburetor on a 1979 chevy c10 400 small block

Choke plate and vacuum break flaps not engaging properly
Submitted: 5 years ago.
Category: Chevy
Expert:  ASEMaster35yrs replied 5 years ago.

Hi, glad to be of help. If the rods are installed correctly, you may just need a simple adjustment. Here are some links with pictures & video to show you how & what to do.


How to rebuild and adjust a Quadrajet


Secondary adjustment video

ASEMaster35yrs and 6 other Chevy Specialists are ready to help you
Customer: replied 5 years ago.
Do you have anything with specs on know the non-electric choke, this thing doesn't have the round plastic deal
Expert:  ASEMaster35yrs replied 5 years ago.
Give me the number of the carburetor and I'll see what I can find. Rule of thumb is adjust so that there is 1/16" opening when cold, at start up. if yours is equipped with a choke pull off you can apply vacuum to it with a vacuum hand tool and adjust rod so that there is a 1/16" choke opening.

Can you send me a picture of your carb showing the choke side?

Let me know if this is a california or federal vehicle.

As far as idle mixture adjustment, attach a vacuum guage to manifold vacuum and adjust mixture screws equally to highest and best vacuum reading. This method superceeds any specs you may find and will give you the best setting for both mileage and performance.


Here's a couple good links on Quadrajet information:


Specs & Tips


Manual with specs for your carb Price: $6.95

Customer: replied 5 years ago.
OK s I've gotten it of to start and idle now, but it dies shortly after. And will not start without gas on pedal.

I've checkedfuel lines and field pump seems to be OK although I will be checking more thoroughly on that today
Expert:  ASEMaster35yrs replied 5 years ago.
Does it seem like it's running out of gas? Did you set your timing at 4 degrees BTDC and re-adjust your idle mixture screws to highest & best vacuum? It is possible you have a bad float in your carburetor or float level set wrong.
ASEMaster35yrs and 6 other Chevy Specialists are ready to help you