87 Caravan carb problems

Hi folks looking for help with a rebuilt Mitsubishi carb. the high idle won't work and it runs lousy until warm. engine misfires and won't idle without extra gass until warm. idle is inconsistant even when warm. All vacume lines look good, doesn't burn black, can't figure it out. It's getting cold up here and I miss my high idle in the morning cheers Roly