vacuum?

LAst week, exp was running rough,on the way home from work, I found that the plug on vacuum port at rear of plenum had fallen off, I re covered it, and it runs OK. NO Check Engine Light. But, when it starts, the idle runs high for about 20 seconds, then kicks down low and goes lower till...

Hey guys! I also am having wierd problems with my 96 MAZDA B2300. over the last few months i have been experiencing idol problems. It likes to either run at 400 or 2200 rpm. when i take my feet off the pedals it goes up to 2200 and when i bring it down in gear it will either go back up or sit...