I ran into this problem. You can test the injector itself by disconnecting it from the harnes and hook it up to a battery and test if it is working.
Put an aligator clip on the possitive side and connect it to the possitive side of the battery. Then connect a wire to the negative side of the battera and tap the other end of the wire on the negative pin in the injector. If it clicks it is working. if not it is stuck.
For the harness-get a noid light. It detects injector pulse.
93 LX Hatch
Mods (for now till I get it running and to the dyno) are built balanced 306 with e-cam, 8.5-1 TRW Forged pistons, Holley heads (61cc) polished and port matched to a GT40 well ported lower and a Cobra upper (plenum extended 1 inch), 65 TB, 80 mm mass air, UPR power pipe, shorty headers and full 2,1/2"exhaust, 36" injectors and S-trim 10-15# hopefully. Waiting to go on after I pass emissions-Stage III Foxlake old school TFS High Ports, long tubes and a new cam (cam suggestions welcome)