A Few Engine Wiring Questions

[Paulpen]

Well the RB25 is in the S13 so sorting the final niggles now

First of all im not getting a 12v feed to this grey wire which is the feed for the injectors. Followed it back to the passenger side and it ends. Where does it connect to normally ?

Secondly the same problem with this white wire for the coil packs I think. Difference is that it seems to go where it is meant to (blue 4 pin relay next to the ECU) :confused:

Finally where does the yellow wire from the purple plug go ? and what does that sensore do / called ?

Many thanks in advance from the always helpfull bunch