"After checking all voltages and resistances, replace cap and rotor. Any ideas as to why this car won't start after setting for 18 months. It ran before it was parked."The problem is in the ignition. Fuel delivery is ok. Just no spark.
I acquired 3rd degree burns up my right arm shoulder and side of my head about 8 years ago when a co-worker did exactly what you warned about....He turned the car over while I was pouring gas into a carb. Use Choke spray, and make sure that there is no chance of the engine turning over while you are under the hood(Note: when you dump Gas down through the Carb if your Engine back fires there is a small chance of the Carb catching fire so be prepared.)
You can do the same with Starting Fluid but you need to be more careful. Have someone else try to start the Engine while you are careful to use only enough Starting Fluid to see if the Engine tries to start.