Car won't Start

I bought this car because of the price which wasnt running properly(hesitation, rough idling, and lose of power. After buying this car I put new plugs and wires and changed the fuel filter, the car ran a little better with same problems. After driving like this a few times I decided I didnt know how to fix it and was gonna take it to a shop but while letting it warm up and died and hasnt started since just will turn over. After the car died the check engine light is now on which wasnt before. Have taken injectors out one by one and theyre not firing, do you think it could possible be fuel pump or ecu/ecm or some sensor. Thanks