so i just finished my swap i have a 98 civic with a b16 in it. i just now took it out for a drive at first it wouldnt idle so i got a flat head and adjusted the idle control thing untill my car idled at 500 rpms but no matter what gear i am even in neutral when i drive as soon as i get to 1700rpm-2000rpm my car starts jerking back and forth and when im in neutral when i give it gas and it hits those rpms its like launch control lol, and fluctuates up and down. but when im driving i can engage and ride the clutch passed 1700 and 2000 rpms and it drives and runs fine. any input or suggestion would be nice thank you.

 

what ecu are you running? is it chipped?

 

Are you throwing any codes ?

First thing to check would be that, maybe swapped map sensor connector incorrectly ?

But before more guessing,

What ecu are you using ? and what codes if any.