help!!! Cylinder 4 not firing
 

So, after finally getting my jdm v2 wrx built from the ground up it was time for a map. Took it to Surrey Rolling Road for Race Dynamics to work their magic and while he was setting the boost map came out to tell me its only running on 3 cylinders. We then checked spark and it was getting spark, he then unplugged the injector and...... no change, engine should have died down/changed tone etc. Next he checked the wiring, its getting 12v, continuity, signal from ecu etc so told me the injector is probably stuck, great, they'd only just come back from being flow tested and cleaned! Got the car home and swapped injector with cylinder 2, fired it up and no change, unplug any injector and car hunts for revs but unplug No4 and no change. I used a bulb to confirm the plug was sending signal to injector and it is. I then did a compression test on cylinder 4 and its holding 160psi so that's good. I'm at a loss! To recap, cylinder 4 is getting spark, injector works and is getting power and compression is good but when you pull the plug off there is no change in engine note. What am I missing???