1991 Chevy S-10 no fire

Hello, do you have the TBI fuel system? With the engine cranking, do you see an injector spray pattern? If no spark at the plugs or injector pulse, I'd look for a rpm signal. What is the litre size of engine?

If there is no rpm signal, no injector pulse. Depending on where the signal is lost, no spark either. If the coil is separate from the cap check the smaller primary terminals for B+ and ground. The voltage goes hot with the key on, the ground pulses engine cranking. If the coil is in the cap, there may be a place that says tach, you can use a testlite on the tach terminal, engine cranking, the lite should pulse. If no pulse, possible causes, pick-up coil-- ignition module. Right now, I don't know where your coil is located?