1992 Chevy Silverado Where to start?

When you first turn the key on, no crank, can you hear the pump for a couple of seconds? Are there any codes? You can run the pump without using the key, terminal G at the datalink connector, it should look like the above picture. Use a jumper with an inline fuse connected to B+ touch the G terminal, the pump should run. Also you need a fuel pressure gage on the supply line, to check pressure. I've seen injector spray patterns that looked good to me while cranking, but the pressure was half of what it should have been.

You could try starter fluid in the TBI, see if it will try to start? There could be safety issues using a flammable spray, the responsibility is yours.