Hi everybody,

I have a 1966 Quadrajet Rochester #7026250. I want to set my air/fuel idle mixture correctly by using a vacuum gauge. I am not sure where to plug it in. It looks like I am missing something. Please see the attached picture. Should there be a fitting/nipple there. If so, which one do I need (part number) and where to order it from?

Perhaps Bill Demmer can help.


Regards,

Robert

 

Are you getting vacuum from that port at any time (at idle or with the throttle blades open)?

If not I'd say is was a casting used for different applications and yours didn't use that port.

 

The metal tube barbs that vacuum hoses attach to are just pressed into the carb body. I've often had them pull out with the vacuum hose. As noted, check to see if the port has vacuum while the car is running. If not, it's just an unused casting feature. If there is vacuum, you'll need to press in another tube barb. Be aware that if that is a ported vacuum opening, you won't feel vacuum at idle, only with the throttle slightly opened.

 

I haven't had time to start the car and take a look at the carburetor. I was wondering, if I need a tube barb, where can I get the correct one?

 

Those come out a lot, I believe that is ported vacuum won't affect idle but any spare or junk Q jet you can grab one off another gently with pliers and twist it out and just use a screwdriver handle to gently bang it into place. or just stick a coarse type screw in it to plug it.