Occasionally Fails to Start When Parked Uphill
Over the past few months, I have noticed that my 2011 Mazda 3 (52,xxx miles) sometimes fails to start on the first attempt. It primarily happens when I'm parked on a hill, such that the front end of the car is higher than the back. I can't recall a specific instance of this happening when parked on level ground, although it's possible it could have. I drive the car frequently (almost daily), but this issue does not happen on the first attempt after sitting for a couple days, because my parking space at home is level. It's only when running an errand and I park uphill for an hour or so.
When it "fails to start" I hear the engine turning over, but it doesn't catch after several seconds. I then stop attempting to start it, wait 5-10 seconds, and try again. The car always fires right up on the second attempt, as if I'm parked on level ground. I have not yet tried holding the key for longer than a few seconds when this occurs, but I will give that a shot next time.
My initial thought was that it's fuel related. Perhaps the fuel isn't being pumped uphill quick enough, but by the second attempt the fuel has made it? This issue happened to me today when parked uphill with less than a quarter tank of fuel. I cannot speak for the fuel level of previous instances of this issue, but I will keep a closer eye.
It was suggested to me that this is a fuel pressure issue, and that my fuel pump is on its way out. I looked up some symptoms of a failing fuel pump (jerking/surging when traveling at constant speed, loss of power while accelerating, decreased gas mileage, failure to start) and I don't seem to be experiencing any of them besides the occasional failure to start when parked uphill.
If anyone could share their thoughts on what the issue may be, or suggest any additional details I should pay attention to, it would be greatly appreciated!