I don't think it's the spark plugs or wires because it's unlikely for all of them to go out at once.
Don't rule this out, I've seen stranger things happen. When was the last time they were changed out? What type/brand of wires and plugs? Check the gap on the spark plugs.
If you have a compression gauge, perform a compression test. I know, it may not seem related but it is. Plus, it doesn't cost you anything; you can always rent one from a local auto parts store, they usually refund the rental fee. By the way, how many miles does the vehicle have?
If you have recently replaced the spark plug wires, spark plugs, cap and rotor, you should replace the fuel filter and check fuel pressure. If you have low fuel pressure, then that's an indication of a bad filter or pump. Also, check for vacuum leaks.
Definitely look into the ignition coil, there are a few videos on how to test them.
If all of the above checks out fine, then you will need to look into the injectors. This is a little more involved. You can remove them and check for obvious dirt and grime but checking flow and spray will rule them out.