i have a swapped 98 200sx se-r sr20de-t with jwt ecu and z32 maf all custom piping hks internal blow off and 72lbs injectors msd. im usings a vacum boost gauge and im gettint 12 to 16 when is starts to surge. this usually happens when the car is idling for 20 to 25 minutes. if i turn the idler screw all the way out i will hear a whistling sound like air and the car will run fine. if i hit the gas pedal to 2000rpm and the car returns to idle it will feel like it wants to turn off. if i turn the idle screw all the way in i will not hear any whistling sound from the intake. also will the system i am running, which coolant temp sensor should i use and which throttle body should i use. any help will be appreciated.

You should be using the throttle body that came with your motor and the throttle position sensor from your old motor, and the coolant temp sensor from your old motor (though they are likely the same).

It sounds like you have a leak. Pictures under the hood would help. Easiest way to fine intake leaks is spray a little brake clean in suspect areas and see if the idle jumps up. Use common sense and don't catch stuff on fire, don't use big bursts of brake clean. With very small leaks you can use a scan tool and look at the fuel trims and see if it goes rich.

I've never took notice of what mine vaccums at idle, but it always stays steady. I think it's inbetween 15-20.

boost leak test you have leaks and if you test it you usually find them. use the damn search button please

Use the usdm coolant sensors and use the tb from the swapped motor.