you can run the 1.6 with the car's original dual point injector system,
if you're stuck on parts.  to go with the 4-point si injector system,
you have to modify the wiring harness.  there's a number of "2-ner"
sites on the web that show you what to do.  but you got to have the
parts!  you could make a harness if you have the connectors, but you
still have to have things like the ballast resistor, etc. which the dx
doesn't have.  see if you can find civic si or 90-91 civic ex parts in a
junk yard.  they'll all fit.