I have a 2003 Mazda Protege5 and I'm having issues with it. First off, the car sat for years without a fuel cap. Didn't think anything of it and yes water got into the tank .I didn't know until after I ran it . After it shutoff I sprayed starter fluid to try to restart it .Explosion! Blew up the air intake and mass air sensor. So I added a new mass air sensor and a cold air intake . I pumped out the tank .New fuel filters, coils, wires, plugs and fuel pressure regulator. Just put in new fuel injectors and I'm having the same problem, I give it gas and it backfires and wants to shutoff. Any ideas or suggestions? GREATLY APPRECIATED!!!! HELP!!!

 

If you did not replace the fuel pump, that might be the cause. In tank fuel pumps can die while sitting. They get gummed up from ethanol and that is the end. In you case of no gas cap, the fuel pump might be rusted etc. inside. Fuel pumps are fairly cheap from Rockauto. You may want to get the cheapest as a test pump and if the car runs, you can get a more expensive one if having the cheap pump bothers you. The pump is located under the rear seat and very easy to change out but make sure the battery is disconnected and there are no sparks, flame, etc. to blow you up. I always keep all doors open on a car when changing the fuel pump so gas fumes do not build up in the car.

 

I did replace the fuel pump, with a used one, but it was a lot cleaner than the one I took out .The gas was milky white when I drained it .So I put fresh gas in and multiple fuel additives .It idles great but when I give it gas it's horrible, no power and dies. I'm thinking now it might be a faulty mass air sensor .I bought a cheap $16 one.

 

If you have not done so, I would take off the timing belt cover and look at the belt, tension pulley, and alignment of the timing marks. Only takes a few minutes to do that.
Bad fuel pumps can run the car at idle or low RPMS but still give it up when more gas is needed or when the engine is under load. I have found most used pumps are bad which is why I don't use them any more. You can get a new fuel pump for $14.00 at Rockauto.