Ok so I put a b16 in my 90 Honda civic SI I changed the plug on the dizzy to obd2(only cause it came with the engine) so Wen I drive my car will die. its like my altunatot won't charge my battery.if I start my car and unplug the battery the car will shut off.Idk wat it is.I took my harness out and sodered the wires but still nothing. Any help is greatly appreciated

 

Does your battery light come on? Did you install the wires on the altenator and tighten them down?

 

I've never had abattery light .and everything is tightened and plugged in

 

Have you had the battery and altenator tested? I would try that first.

 

Brande new battery and altinator.I just had the altinator tested yesterday and it passed

 

Your alternator is NOT working if you can't take the positive battery cable off and have the engine continue to run.

Remove the alt and have it tested - most autoparts stores can do this (usually for free).
I know you stated that it's new, but you could have gotten a brand new malfunctioning one.
If the alt is good, then your wiring is bad.
Simple as that.

 

Couldnt have said it better myself 4drEF.