Most likely you will never need them. The grey can be used to activate something electronic with the addition of a module (e.g. boost controller) and the purple can be used when staging to limit the amount of alky being sprayed. Purple works like this... When staging, the purple wire should be grounded and when you launch the ground should be lifted. This could be done via a relay on the brake pedal switch as the instructions suggest. Just be careful if you use it as if it stays grounded for whatever reason then your spray will be limited all the time instead of just when staging. Most likely you will never need either one... Tape em up and forget about em. (Although I use the purple for staging with a relay hooked to the brake pedal.)
Grey wire is aux output(ie, external boost controller), violet is a negative trigger input " grounding this wire reduces injection pump speed to initial pump pressure for staging applications while drag racing. Intended application is E-brake switch'
Bryan
you can, but in that case and IMO it will be more trouble than its worth to use... Ask Julio for the instructions with the purple wire in them, all you need is a relay and a foot of wire or so. I'd say almost no one uses this wire though... I would only say you need it if you bog or have a rich condition you cant correct off the line.