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Adjust 68 2v 2100 Carb w/ Auto Tran & A/C

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How important is the vent hole on top of the carb?  The book says it's supposed to be open at idle then closed at throttle.

Also, when the engine is warm, should manually closing the butterfly cause the engine to choke off and run rough or cause it to run faster?  My old 1979 Camaro with a 305 2v would run smoother as the engine warmed up and the buttlerfly opened.  If I closed it manually it would make it run rougher and choke it.  This carb seems like the opposite in that when the engine warms up and the butterfly opens it. manually closing the butterfly increases engine speed which seems like it runs better that way.

Then you don't have something adjusted right.  When the engine is hot and you manually  close the butterfly, it should choke it and eventually kill the engine.   Do you realize this thread is a year old?   ;D

That's what I'm trying to figure... and yes, I know I started this post last year, tried many adjustments, then had you rebuild the carb for me just a few weeks ago... but something just isn't quite right. 

I tried plugging the vacuum ports at the manifold, but it didn't seem to change anything.  The car runs at idle best/fastest when I hold the 'fly at about 1/8" open or from closed.  The mix screws are set 2 1/2 turns.  Also the 'fly never fully closes... the 1/8" open is about where it starts, then it quickly opens up after start.  it feels like there is spring tension holding the 'fly open.

I open/close the vent on top to see if it did anything, but I don't see how it has any effect on the car whatsoever.

This is really bugging me so I'm reaching back out to find some test to run or get answers.

There is a spring tension holding the choke butterfly open after the engine warms up.  That's what that black round choke system is all about.  You can adjust that by loosening the three screws, then turn the black round thing until the butterfly goes to where you want it, then tighten down the three screws.  Do this when the engine is cold.  There is nothing wrong with that carb.  You must have a vacuum issue.  It is difficult to repair an engine on the internet.   ;D

Totally agree with trying to fix this thing over the internet  Folks that have lots of experience with this would probably find the problem in a few minutes, but for  a novice like me, I'm just getting frustrated.

It looks like my carb may not seat tight to the spacer/manifold as it appears to be a little wet around the base.  Is it ok to use "form a gasket" material that is for use with gasoline?

Any suggestion where else I should look for a vacuum leak?  I already have the vacuum ports blocked at the manifold, so I'm clueless as where to look now or what else might be causing the problem.


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