Dreams Fusion

Hi, I have a mitsubishi lancer cs2a year 2005 which had 4g13 engine when I bought it. I have recently put in a 4g93 1.8 engine which is running OK. I love the feel and drive of this engine but there is a slight problem which I can't find the solution for. On instant throttle the car slightly hesitates which sounds like a power cut. I checked the ignition coils, spark plugs, fuel pump, injectors etc. Everything is fine. There is this pipe laying open in the engine bay which is coming from a device which is mounted just below the area where throttle Body is mounted. There are two pipes one is going in the same device as U but the other one is laying in the engine as I have mentioned. Occasionally I can hear bloop bloop sound as well from it. Any idea where this pipe should be mounted and perhaps this is creating the vacuum leak. I don't have any idle or stalling problems. Any help will be appreciated. Thanks.