340 idle problems

when i choke the air horn of the idle does not go up.when i take the cap of the small manifold vac port to put the gauge on the idle jumps up 3or400 rpm, this is with the double pumper.i acidentaly had the timeing up to 18 initial and it ran grate.14inchs vac nice low smooth idle. put it back to 10 then 12inches. if i put the avenger on it would shut of below 1500.I have bin messing with this for a long time and am running out off pationce.I had the manifold machiened put sealer on the gaskets steel plate under carb I am wondering if their could be a problem with the carb.I know the vac is a little low