ive got a 99 sir aka(si) in the states recently dropped the b16a2 back in after spinning a bearing in the b20 block; however the b16, when it is cold out it doesnt seem to wanna start, after maby around 10 keys itll start however it seems to spudder and sound as if its missfiring. if i give it gas itll be really really slugish untill the motor warms up for 1 min or 2. but after the 2 min go by it idles at about 1500, and after a quick drive it idles at 2grand going up and down from 1 -2 grand.like i said only happens durring the cold weather, never had any trouble starting in + weather.

 

it sounds like IACV on the Intake manifold is the problem, i had a problem like this, try taking it off and cleaning it and clean the gasket on it too

 

Be sure to disconect the battery before cleaning the AICV. Also, did you give the motor a tune up when you swapp'd it? timming belt, water pump, spark plugs, wires, clean fluids. Peace.

 

yup new timing belt, and bought plugs from honda for 90 dollers. motor was running great with the b20 block once i swapped in the b16 block it had that problem, but yea im ganna check it out and give it a good leaning.