#3 injector w/ no power

[Wheels Up]

Hello all. I'm pretty new to the 240SX game. I just picked up a stock 1990. I have searched the many forums out there & cant find an awnser to my problem( many threads on the swap harness though). As it states in the title of the thread. I'm getting no power to the #3 injector. I have no books to go off of right now. So I'm not sure what controls the injectors( maybe just the ECU) BUT is there anything between the ECU & injectors that I can check? Like a resistor pack, ect..?

The previous owner cut the wire & installed a new plug but that isn't the cause.
I have no idea what color the wires are that come off the ECU that I should test. I'm going in blind right now.

I got the car not running a few days ago. But got it going now. After a new fuel pump & fuse( in the engine bay). It runs great besides the fact that #3 isnt firing( not to mention they had the firing order wrong).

Thank you for any help that can be provided.