240sx 5spd

Hey i have a racing tac. i have it all hooked up well i tried anywyas. here is my problem. the tac has a green wire. and i know that green wire goes to my disbutor but the problem is my wires on my disbutor are black/white, black, and white. i tried them all and nothing worked. it worked a lil bit cuz the needle on the racing tac was working but the needle was either going backwards and not forwards or it wouldn't work at all?

can someone help?