Why would the car fire up for about 3 seconds.

Sounds like it's in theft mode. Factory anti-theft systems are real effective at keeping owners out of their cars, and GM's are some of the best.

I show listings for both fuel injection and a carburetor for your model and year. Now that I know it was sitting for years, if you do indeed have a carburetor, chances are the fuel has evaporated out of the line from the tank to the fuel pump. Often the fuel pump won't prime at the relatively low cranking speed. You may need to pour a little gas down the carburetor multiple times before the fuel gets drawn up to the pump. Until that happens, when you look down into the carburetor you won't see two nice streams of fuel when you move the throttle.

Besides getting fuel drawn up to the pump, it also has to fill the float bowl in the carburetor. The fuel level has to get high enough before some will get sucked into the engine.