So I just got my new 383 running recently and thought I had a good handle on the tune but then today I was driving home and it started to idle rough. A little smoke started to come out the tailpipes (rich black not oil blue). So then I get it home with no other real symptoms and let it cool so I can check things out.

So I went out and started it and it seemed to idle a little high but smooth after getting cool so I could touch the motor. So I started by trying to reset the idle mixture with the screws and discovered I could seat both of them and the motor seemed to run fine!!! I have no idea what to look for but I suspect there is some sort of fuel leak that is keeping the thing running.

Help!
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Oh sorry this is not my car motor its a Q-jet 383 with no computers at all.

 

check for air leaks ,run both screws in ,with filter off place hands over top of carb.should cut right off ,if not you have an air leak ,the running rich sounded like the float was stuck,while cooling extra gas ran in manifold and evaporated hope this helps,jimmy

 

but if I run both the screws all the way in how could it even run? when I did that it idled like it was fine at about 900 rpm...

 

It sounds to me you have a vacuum leak and posibility of floats sticking. Check your primaries and secondaries and make sure they are not dripping fuel.They should not be wet inside your carb . You might have a dirty needle valve causing one to stick open and fuel getting bye. You just did an engine swap and it does not take much to get a needle valve sticking. After you shutt your motor down watch from top of carb and see if it is getting wet on either primaries or secondaries.

 

Will do.