The injectors actually use a reduced voltage, something like 5-7 volts.
^^I believe this is wrong^^... the injectors receive a full 12VDC (from usually from a fused/relayed source) and the ECM breaks/makes the ground (via D14 & D16) to fire them.
As I recently finished the TBI swap on the Moss, this stuff is fairly fresh in my mind. The first step to intelligently troubleshooting is double checking the obvious! Confirm the connections are good, that fuel pressure & flow are within spec, & that no codes are being thrown.
Do you own (or have access to) a code scanner or an ALDL cable/laptop?