Isuzu Rodeo Question Fuel injectors won't work

Engine problem
Isuzu Rodeo Question 6 cyl Two Wheel Drive Manual 170000 miles

3.1L V6 with throttle-body FI (2 injectors). Problem is sometimes it starts, sometimes not -- now it won't start at all. Throttle body is bone dry - injectors are not releasing gas, however the car starts easily with starting fluid. Fuel line pressure is good to the carb. Fuel injectors are new and properly seated/sealed. ECM relay + FI relay + fuel pump relay all good. Checked fuel injectors with a meter - both show continuity (coils ok). Checked FI connectors - on each side, I get continuity across both pins, and from one pin to ground. Recently replaced:
- MAP sensor
- throttle position sensor
- O2 sensor
- idle air sensor
- PCV valve (unrelated, but what the heck.)
- all carb vacuum lines

I am completely baffled what to check next to get the injectors to fire. Thanks for any advice you can give.