Hole in Carb: Vac leak HELP! What is this?

Hey Guys! Found a source of a carb vac leak. What is this hole that is under the elec choke assembly? I put my finger over the hole and you can clearly feel the sucking and the hissing goes away. Is this supposed to be like this? Nothing in the Eddy service manual addresses this hole. Carb is an Edelbrock 750 elec choke.

Thanks!

I think hole is where you are supposed to hide your weed.

It needs to be a lot bigger than this....

I thought the stuff the kids have today was much more powerful - so in theory you don't need that 5lb bag anymore??!

I take it the pic is upside down. Does that carb use a choke piston inside the choke housing ? Ron

Doubt this will help - but this is a pic of the E-Brock in my Dart. I have a manual choke - but the holes are drilled for the electric.

This is the newest version of the E-Brock - I think it is a "Thunder Series" or something.....

No, it's correctly oriented. I think the choke mechanism is operated via a coil in the housing. Thanks.

Thank you.

Won't the gas run out like that?

Looks to me like a press-in vacuum nipple is missing.

The Ebrock choke uses a pull off piston, vacuum operated.

http://www.edelbrock.com/automotive/misc/tech-center/install/1000/1478.pdf

LOL...

I found out it's there to help cool the electric choke. It's normal and to not plug it.

The picture is upside down.

I think its a lycoming aircraft engine they have an updraft carb on the bottom of the engine...{sorry could'nt resist}

The pic is upside down. I was not sure but I thought that used the choke piston in that housing (not an external choke vacum pull-off) which has vacum to the choke piston in the housing since it is the choke pull-off piston and it looks like maybe a plug or something is missing from the hole. Many older carbs before they used electric assist and electric chokes had the vacum that leaked past the piston go to a threaded fitting by the choke housing and that was hooked to a tube that ran down through the exh manifold and back to the carb airhorn as it pulled fresh air from the carb airhorn down through the exh manifold where it heated the air and then it was pulled into the choke housing to heat the choke coil as the eng heated up. But this carb looks to be set up with the full electric choke and does not use the heat line like they used years ago but with the choke piston in the housing it still has vacum in the housing to the choke piston to open the choke some when started. My guess without a better look is a plug should be in the hole. Ron

What Ron said, you gotta plug that vac leak

Thanks Ron!! Funny, on my screen the picture isn't upside down.

There should be a welch plug in that hole. And a rubber o ring between the choke housing and carb body.

the 1406 carb on my dual quads has that hole, from the factory, and it works great.

i just pulled a choke assembly apart. that hole/passage doesn't connect to the vacuum port of the carb or the suction side of the choke piston. i believe it to be a relief port (probably backfire relief) for the body of the choke assembly. if the assembly is carefully looked at you'll even see a small screen in the relief passage. it's supposed to be the way it is. i also think the passage could be considered a type of vent,

Here's one I pulled off an Eddy. OP, I don't need this- PM me if you want it. It has no hole. And that passage is connected to the inside of the choke housing.
Edit- couple of pics of AFBs with heat tube fittings in that spot. Cold air to cool the electric coil? I'd prefer no vacuum leak.

I figured if the picture was right side up the car must be upside down.

i always thought upside down was correct on moparts?

doing more thinking,and knowing the hole/passage is a vent to the atmosphere, this thing could also relieve some temps from a constant 12v heat source. the screen definitely keeps stuff from getting in but will let stuff out. how many times have you seen the black plastic covers melted and drooping?

DO NOT PLUG THAT HOLE.

You have the vacuum actuated piston inside that has vacuum on one side and that that hole is the vent on the other side.

Whomever says plug it doesn't know what they are doing.

Actually I do know, at least enough to ditch the junk Eddy and get a Holley.
Edelbrock added that "cooling" port rather than make the choke cap out of bakelite as the early caps were made of. See above pic of early Eddy choke housing- no hole.

If the picture had been right side up,a lot of confusion could have been eliminated by seeing the hole is in the bottom of choke housing and not the carb.That's what happpens when everyone uses their i phone for posting pictures!

The only "vent" for the choke module is the opening in the bottom of the choke housing below the plastic cover (usually threaded).

You are just saying what they did with the older carbs before they had electric chokes basically and I can see it makes sense. The choke piston in the housing does not had a perfect seal or rings or an o-ring on it as vacum leaks past the piston and on the older carbs the vacum source was a slot in the choke piston housing that only pulled the piston as far as it could until end of the vacum slot gets uncovered by the piston as thats as far as the piston pulls and then you can bend the linkage to adjust the choke pull-off opening. They always did as I said earlier and used that vacum source which is basically a small controlled vacum leak as it pulled fresh air from the carb air horn through the exh manifold to heat it and into the choke housing to heat the coil. Almost like a PCV system in the fact that it is a small vacum leak (source) they use and just make up for the small amount of extra air in the carb adjustment. Its always been more or less to me a controlled vacum leak used to draw hot air into the choke so I can understand that it can still be a small controlled vacum leak like was used for years and years on the older carbs. It may be the vacum leaking past the choke piston and if it is not there and the choke thermostat is sealed to the housing then it would just build up vacum inside the choke housing. It may just be to vent the vacum leaking past the choke piston to outside and if thats what they did then they made up for the small vacum leak in the carb adjustment as was done for years. I have not heard of any reason for it to be here to cool the electric choke as that would kinda defeat the reason of what the electric choke coil does. At least I have not seen any electric choke coils need to be cooled after they heat up while the eng is running since most have temp controls in them. Ron

I don't believe I said anything about cooling.

That vacuum operated piston will not work if one side is not vented to atmosphere.

No I did not say it was you but someone else said something about they did it to cool the electric coil as I was refering to them about that.
From a technical standpoint you are right as of course it needs atmosphere on one side for the vacum (low pressure area) to really work since really atmosphere pressure really pushes rather then vacum (low pressure) pulling on anything. But I really dont think that choke cap is sealed that well where the pressure/vacum would even out on both sides of the choke piston so it would not work. All of the carbs like this that I have worked with over the years are the older ones that do not have an electic coil on them as they all used the coil heated by hot air and the vacum that leaks past the piston to pull the hot air into the choke housing. I have not really fooled that close with many of the newer Eddy carbs like this one that use the electric choke with the housing and piston on the carb as this one. The ones I have fooled with are like the ones my brother uses on his dual Eddy carb setup as most Mopars that use well type choke coil and the external vacum break diaphram. But I do agree with you as with any vacum anywhere you need to have atmosphere pressure on the other side to work and the older ones all did since they used the atmosphere pressure side to feed the hot air to the choke coil since the choke piston is not sealed real good in its housing and the vacum leaks past the piston. Ron