fuel problems on 1991 GMC S15 Jimmy

I have a 1991 GMC S15 Jimmy with a 4.3L V6; I have fuel pumping to the throttle body, but the injectors aren't spraying any fuel. I need to know what tells the injectors to work so I can fix the problem.

Asked by for the 1991 GMC S15 Jimmy
Beleive the computer uses crank and cam signals for injector pulse. If crank sensor is dead you will have no spark. If cam signal is lost the computer will use the last known value, but can be lost if battery goes dead or is disconnected.
When the Jimmy died, and I tried to restart it the battery didn't have enough juice to start it. Didn't realize the injector problem until I got it towed to the house today. So I'm probably needing a new crank sensor and battery both?
I double checked info and andygrace is correct, the vehicle uses the distributor signal for cam and crank position, will need to check the signal from the distributor to the pcm.
1 more answer
A 1991 4.3L does not have cam or crank sensors.It goes off the signal from the distributor sending the signal to the computer.