Engine cranks but does not start

I've got a no start it cranks and a brand new starter, brand new battery, brand new battery cables, and a brand new BCM. I've checked the fuses, the relays, replaced all those. I even took off the panel and send it down anything that looks like a previously blown. my serpentine belt is brand, new brand new timing chain, top dead center was reached. it turns like it wants to start but it just will not. I sprayed some stuff still going to start. I bought this car used I have found under the dash panel at six pin that I have no idea where it goes to it's light green brown black pink red and gray it's attached to the wires that go to the BCM but it's it's off on its own. does anyone know where this goes? is that my cause or is that my reason? I have been working on my car for 5 months I need to be done.