1997 GMC Sierra Not starting

First, so you dont pour too much more gas down the cylinders, remove the fuel pump relay, change the oil and filter, then use either a noid light for your injectors, or a DVOM and see if there is power to ALL injectors while cranking the engine. Noids are cheap and can be found at all parts stores. Pressure in the rail is good, but if the injectors dont fire, no start results.