injector just stopped working

[burba1269]

Hey guys, I've done a lot of reading and can't quite seem to find what I need, but I got a lot of good suggestions. I recently finished turboing my KA-E and was in the process of tuning it. Well all of a sudden my motor started missing while i drove it, so I pulled back into the garage and found that my number 4 cylinder was not firing, I'm getting spark but when i pull the plug it's dry, telling me that it isnt getting any fuel. I pulled the fuel rail and checked the injector, it passed an impedence check and also put 12 volts to it to and could hear it click and shoot out fuel, so the injector mechanically works, my next test is to hook up a light to my injector harness and see if im getting voltage on the line, what would cause 1 injector to just stop working, especially if in fact the harness is not putting outo voltage, is there a relay i should check, could it be a fuse, I would think that a problem like that would cause other injectors to act up. Any help you guys can give is great.

[burba1269]

oh, and my ecu is not throwing any codes, if that helps. I know for a fact my o2 sensor needs to be replaced, the wiring melted to the header at some point and i have to redo the wiring, but that shouldnt affect a cylinder not firing i wouldnt think.