Engine idle - vacuum question

[investig8]

Hello all, I hope you are bundled up, warm and enjoying the week. I have been trying to get Fiona to idle a bit better as currently she spits / coughs every couple of minutes like she's running lean. However, the idle adjustment screw has no effect unless I run it all the way in to the stop... and then of course she dies. My question is: Some time ago I removed the vent tubing that runs from the elbow between the air breather and carburetor to the distributer and I think master cylinder. I didn't plug the outlet holes because I didn't think it would matter as they are "upstream" of the carburetor. Was I wrong in this assumption? If not, any other input would be greatly appreciated.
Thanks,
Dennis

[Elwood]

They should be plugged, because they will allow unfiltered air into the intake system.

[NAM VET]

When I mucked around with any ETW1's needle and seat, doing it incorrectly, my engine wouldn't idle well at all, and my idle needle likewise had almost no effect. It wasn't until I correctly set my incorrect float level, and which of course requires removing the long idle jet on the top of the bowl cover, and blew it out, and then set my float correctly, per a recent post with pictures of this a month ago, that my engine idled and ran fine. If you haven't already unscrewed the long top needle jet, might try that first. And the pre carb two fittings that ventilate the coil on a military distributor, are important for reducing ozone or something line that in the coil. If you don't have a military carb, I agree that best to plug or cap the two vent holes. hal

[refit1701]

The idle mixture screw only affects the carb when the truck is at idle. I have made this mistake before. I tend to run with the "cruise control" pulled out to advance the idle speed just a little. Remember that proper adjustment of the base idle mixture can effect the carb up to 20 mph, that's when the high speed circuit totally takes over.

(Yep, I've been studying the Carter theory of operation manual the last two weeks. Everyone should read it.)

[investig8]

Good information, as usual. I appreciate the responses and will give it another try...
thanks,
Dennis