Edle 1406 vacuum leak below choke housing in casting

[coop]

Edlebrock 1406 performer carb. If you are looking at the choke housing at the below right there is a small hole in the casting of the carb and you can hear it sucking vacuum. If I put my finger over the hole it stops the vacuum and the engine slows down
is this supposed to be plugged or is it part of the choke function? it has a electric choke.

[70_F100]

A picture of the area you're talking about would be helpful.

[coop]

here is a picture the hole at the lower right of the choke housing

DSCI0057.JPG

[flyboy2610]

A vacuum port missing its fitting?

[coop]

Should it be plugged? I checked out my carb manual and the exploded view of the carb shows the port, the picture shows a nipple on it. They call it a choke vacuum port and there is also a filter in the housing, I guess to filter the air coming in. My carb just has the hole, should I plug it? like I said if you put your finger over it the idle drops someone must have the same carb out there what is yours like? Edlebrock 1406 600CFM Performer W/Electric choke.

[cdeal28078]

I don't know enough about that carb to say from a picture but is there anyway the choke housing is rotated wrong and leaving the pull- off port open? I know a Holley has a vacuum port to the choke and figure yours does also. Anybody else think that might be the case?
If it is a vacuum leak it needs to be plugged one way or the other regardless.
clint

[70_F100]

That's probably the way it's supposed to be, especially since you say it has a filter in it.

On the older hot-air chokes, the carb pulled vacuum through the choke housing. It did that through the heat tube that was run into the exhaust manifold. There was always a tube through the manifold that opened to fresh air, and this tube was heated by the hot exhaust gases.

On a lot of engines, there was a tube attached to the open end of the heat tube that went back up to the top of the carb and pulled filtered air through the system, but some manufacturers just let it breathe unfiltered air.

You could block off the heat tube provision on the choke housing, and it, too would slow down the idle.

I personally wouldn't close it off, because I feel sure the carb was engineered and tuned for this extra air.

Probably the best solution is to contact Edelbrock with your question, since it is a new carb. They will know the correct answer.

[coop]

I searched the great internet and think I found the answer to that vac port. What I found is that it is a metered vacuum and it helps keep the electric choke element cool. And it should not be plugged, if it is it will cause a rich mixture. The manual chokes are blocked off with some kind of tape. I am going to call Edelbrock and see what they say.