Vacuum line

[Jim L]

Does anyone know where the vacuum advance line from the distributor goes on a non computer Quadrajet carburetor?

 

[Built6spdMCSS]

The port that doesn't have vacuum at idle, rev it up then it pulls.

 

[79 USA 1]

This diagram should be what you are looking for.


The evap canister line will be on the base plate, distributor advance should be higher up (Above mixture screw) on the main body. (Red arrow)

 

[69hurstolds]

Million different ways to get vacuum to the distributor, but only two choices of types.

The carburetor body vacuum ports usually are what they call ported vacuum. Which basically is saying at idle, you don't get vacuum, but when the throttle starts to open, so does that port which then sees vacuum depending on throttle position.

There's also called full manifold vacuum, where the distributor vacuum can is hooked up directly to the intake manifold or attached to a carb baseplate port which sees full-time intake manifold vacuum. If in doubt if a port on the carb is above or below the throttle plates, when idle speed, here's a quick check- pull the cap/vacuum line from the carb port and put your finger over the end. If you feel vacuum, it's full time. If you don't, it's ported. This is only at slow idle speed, though, and assuming there's no clog in there.

There's always 2 schools of thought on which type is best for your car. Try one, then the other. See which one gives you better driveability. Some people swear by one or the other. But it really boils down to how your car reacts. Once you open the throttle to a certain point, it doesn't make a difference. It's around town stoplight to stoplight where you'll notice.