carburated dodge truck won't idle

[66plyValiant]

hey guys, recently I bought a "new" caburator for my restored 79 dodge 1/2 ton. its a carter 2 bbl and looks new as the guy suggested it was so I paid $50 for it. at idle it won't run for anymore then 5-10 seconds and dies out but on fast idle it works fine, I tried another carb on it and it works fine as it should. what should I look for when I take the new carb apart? what would be causing only the idle circuit to not funtion? any advise is appericated its a 318 CI by the way

 

[RustyRatRod]

first thing i would have checked for before removing it would have been a vacuum leak. If it will idle with the choke closed or partially closed, it has a vacuum leak. That would be the absolute first thing to rule out.

 

[66plyValiant]

but with another carb it will run fine even with the same gaskets under the carburator...

 

[nothingbutdarts]

put the gasket on the new carb while it's upside down & check that there are no areas that can leak vacuum.

Is it the same type/model carb. as the old one?

 

[66plyValiant]

its identical, just bought it because it was a good deal

 

[RustyRatRod]

but with another carb it will run fine even with the same gaskets under the carburator...

Did you see where I said it was NOT the carb? carbs can have internal vacuum leaks, not to mention intake leaks around the carb base. you asked for opinions and you're arguin with um. Ok....

 

[nothingbutdarts]

If you can get to run long enough, look down inside the carb while it idles and see if any gasoline is dripping out of the boosters?
If so the float could be set too high.

 

[66plyValiant]

thank you nothingbutdarts I will check it out!