96 Chevy S-10

Could be the ignition switch is failing

Crank and will not start-Do below and get back with some testing results:

Get a helper disconnect a sparkplug wire or 2 and ground it to the engine at least 3/16 away from ground -have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, Do you hear the fuel pump come On when you turn key on? If not check fuel pump fuse and fuel pump relay if so, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs, coil's resistances, distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it.

Your fuel pressure is too low-4.3L 60-66psi(4.2-4.6)

Consider replacing the fuel pump if the fuel pressure regulator and nut kit is not leaking also check the fuel filter

Disregard the FPR and the Nut kit-you tested the injectors therefore its a TBI system-Where did you get your fuel pressure-The fuel pressure on a TBI is 9-13 psi? I'm confused here-whether it a a TBI or CPI Vortec