All you have to do is get any Haynes repair manual and check to see which color is -, andwhich is +, usually with injectors it does not matter, they will work either way.
Basically, you should be able to get away with just connecting the wire, I suggest first connect with a good crimp tool, and the solder the crimp connection, then heat shrink, them cover with the corregated tubing, that how I have done all my injectors on my projects.

Dean