1962 rpm increases when air cleaner goes on?

[aa010175]

I have a stock 390 motor in my 1962 Thunderbird. I rebuilt the Stock autolite, 4100 carburetor and now it won’t idle at anything under 750 RPMs. It just quits after that and when you do have it running and you put the air cleaner on the RPMs increase considerably. What would cause an increase in RPMs by putting on the air cleaner stock? thanks, Dave.

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[Tom Alpers]

Did you take apart or adjust the linkage for the secondaries? Maybe they are not closing all the way. What about the air cleaner hitting some of the linkage?

 

[74 Harley]

You could also have a vacuum leak.