MirandaJ1223

I have a 4160 Holley carburetor on an Edelbrock Performer manifold on my 350.

The car has ran rich since I bought it. Today I decided to adjust the mixture screws and timing. I put my vacuum gauge on the carburetor vacuum line and the reading was 0. That is the port that the vacuum advance was hooked up to.

Since I now have electric headlights I had an extra manifold vacuum port and switched the vacuum advance to that. I wasn’t able to test drive because it has rained all day.

I have 2 questions.

1) is it ok to run vacuum advance off manifold vacuum

2) what do you think I need to do to fix the vacuum from carburetor

4-vettes

Yes you SHOULD run your vacuum advance off your manifold vacuum.
2, the port you hooked up to that reads zero is ported vacuum. Above the throttle plate at idle. Put a plug on it and forget about it.
When adjusting your carb. Hook your vacuum guage to manifold vacuum.

Rescue Rogers

ported vacuum for vacuum advance is for emissions...dont use it.
ported vacuum doesnt show a signal until the throttle blades open. No need to fix yours
all engines have vacuum, it is the same vacuum you would feel putting your hand on top of the carb intake.
vacuum is also called a signal when referring to your ports and venturis or boosters

Jebbysan

There is nothing to fix....ported vacuum nipple has no vacuum at idle....only when throttle blades are cracked open.

Jebby