A month and a half ago one morning I accidentally drove over a concrete barrier. I then ran errands for the rest of the day through the afternoon. At one point my car stalled out in the middle of an intersection briefly, but I started it back up right away.
I then arrived home in the evening, and an hour later, got in the car to go back out, and the car would not start. It would only turn, but not catch. I attributed the issue to the car running over the barrier earlier in the day, and had it towed to a collision place to find the problem.
They took a look, and said there was only minor cosmetic damage underneath.
I then had the car towed to my mechanic, who could only find that a battery terminal was bad, and the throttle body sticky.
The terminal was replaced, the throttle body cleaned, and it was assumed fixed, so I picked up the car.
The next morning I was driving into the city in some heavy stop and go traffic for about an hour when my car started to stall out on me again. I was able to get the car started a few more times to get to a safe place on the side of the road to call a towing company.
The car was acting as if it was getting no fuel, so I was feeling that I had done something to damage the line to the fuel pump, and/or the pump itself.
Had the car towed back to the mechanic, who told me he was basically at a loss about what could be wrong, because of course, it started with no problem after he got it.
Since the car was running, I decided to take it to a Mazda dealership a few miles away for them to run diagnostics.
They found several things that the little car needed, but the thing they found that could be related to the car not starting, was that the fuel pump was running at half capacity. They quoted over $800 to fix it, and my mechanic offered to do it for almost $300 less, so I chose the latter. He initially tried to replace it with an aftermarket pump, however, it did not fit correctly, so he had to replace it with one from the Mazda dealership.
The car was ready on a Friday, and drove it around locally during the weekend with no problem.
The following Monday, I drove to school, and then to my clinical site with no problems. On my way home for the day, I was running low on gas, and decided to fill up my tank in order to see if I was getting better gas mileage with my new pump. When I got back in the car, it would turn, but the engine would not catch.
I had to have the car towed from the gas station back to my mechanic that evening.
My mechanic researched the problem some more, and he said he read that this model has been known to have a problem with one of the relays associated with the fuel pump. He replaced said relay, and I picked up my car the day before Thanksgiving. Again, I drove it around the holiday and with no problems until the Tuesday after Thanksgiving, when the car started stalling out on me again.
The video above is what keeps happening. It will turn, but rarely catch and start up again, and when it does start up again, it stalls out immediately after.
Input/comments will be greatly appreciated.

 

How frustrating! Intermittent problems are the worst to diagnose. Tests only yield useable results if they are done while the problem is happening. Are there any codes set? Maybe call around for shops with a data logger that you can use until the data is caught during the problem. Another option is an inexpensive wireless obd interface (On Amazon or ebay) and download a mobile obd app that can log data. The important thing to know is that data while the car is running good is only good for comparing the data to when it is stalling out.

 

Yes they are! I've been in tears over this. Thank you for your helpful comment.