first of all i want to apologize coz my post is gonna be long please have the patience to read it. i have a 94 civic coupe with a b18c gsr motor,i noticed that my car is idling funny sometimes it idles around 300 rpm but usually it idles around 700-900 rpm plus my car is kinda like jerking especially in first gear,it stalls and backfires at lower rpms let say 2000-3000 rpm range doesn't matter what gear,so i changed the cap,wire,plugs and rotor but it's still doing the same thing.i took it to a shop and tell the mechanic to check the timing and tell him the symptoms and he said it could be the distributor itself,while he's checking the timing he noticed that three vacuum hoses are not connected one of them is for the fpr i'm not sure about the other two lines,so he fixed the vacuum hoses. and car runs fine for few days now it start acting up again, i don't know what's wrong do you guy's think he's right about the distributor? and the guy that did my swap put my old d16z6 o2 sensor to the gsr motor maybe that's causing the problem too coz i'm not sure if they were interchangeable. please help thanks in advance.

 

mayb u should clean ur iacv? i dunno

 

Could be the IACV (clean it)....also try changing the O2 sensor, if all else fails-change the distributor $$