cranks but won't start?

When you first turn the key on, the fuel pump should run about 2 seconds to pressure up the system. Maybe you could go to one of the parts stores and rent a fuel pressure gauge that attaches to the fuel rail through the shrader valve. It would tell you if you have sufficient fuel pressure to start.

If it was electrical, the engine wouldn't start at all. Starting with the aid of the starting fluid tells me it's a fuel problem during initial start. That's all I could think of.