Sorry to drag this up guys but need some info

I have a new engine loom but dont know who made it it has all the wires labelled but I only have 4 wires for the car loom
Tacho
fuel pump
water
ign
Thats all they say ok the 1st 3 are obv but only 1 ign what do I do about it?

Is it scrap now?

How do I know what wire on the loom to connect it too?