78' Malibu Carburetor Replacement

[ZeblodS]

Hello,

I bought a Chevrolet Malibu, with a 78' 305ci engine.
It uses a Rochester 2GC carburetor which wasn't working properly.
So I ordered a new one from RockAuto, which was the replacement model for my engine.

The problem is, the new carburetor has an additional input compared to the carburetor I already have. And I don't know what needs to be connected on it. It's the input showed by the green arrow on these pictures:

Thank you.

 

[Texas82GP]

That looks like it should connect to the evaporative emissions canister (charcoal canister). Does you car still have it?

 

[ZeblodS]

Thank you for your answer.

About the canister I have no idea... What does it looks like on my car?

Right now I "clogged it" with a pinched hose, if I have no canister should I let it free or clogged?

[EDIT] I looked on Google Image for the canister, I have nothing that looks like it under my hood...

 

[Texas82GP]

Maybe your canister was removed by a previous owner. My concern with plugging it is that the float bowl needs a vent. I'm not sure I would unplug it and let it vent under the hood though. If it was my car I would put the canister back in it. Hopefully others will chime in.

 

[ZeblodS]

It's possible it was removed like you said. Previous owner also removed the air conditioning system and the cruise control from under the hood (I have everything... in a box of parts).

I followed your advice and removed the clog. I'll see if it's working fine tomorrow on my way to work.

I'll see later for putting back everything that has been removed...

 

[ZeblodS]

All right, now that I know what to search it's easier. I found this :

So it's indeed the "External Vent To Canister". Right now it's connected to nothing, and the carburetor seems to work fine, I'll see if I can fit a canister back again under my hood.

But I drove for a week (150 miles) with this vent clogged, could I have damaged the bowl by clogging the vent and driving like that?

 

[Texas82GP]

All right, now that I know what to search it's easier. I found this :

So it's indeed the "External Vent To Canister". Right now it's connected to nothing, and the carburetor seems to work fine, I'll see if I can fit a canister back again under my hood.

But I drove for a week (150 miles) with this vent clogged, could I have damaged the bowl by clogging the vent and driving like that?

No I dont think you damaged anything.

 

[565bbchevy]

Maybe for the time being just put a small filter/breather on the end of a piece of hose coming off the carb.

 

[Clone TIE Pilot]

Buying a reman carb is a huge mistake. The carb they sent you has an extra barb because it is likely they sent you an incorrect version of the 2gc, for your application. Reman carbs are often cobbled together from mismatching, parts, incorrect spec parts, generic spec parts, bizarre modifications, Jerry rigging, and poor workmenship. You should have had the original carb rebuilt by a competent rebuilder.