2011 - Sometimes Fails to Start on First Attempt
 

Over the past few months, I have noticed that my 2011 Mazda 3 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.

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; however, the car runs fine once started. The only issue is starting when parked uphill, which leads me to believe it's not a bad fuel pump.

This doesn't seem like an issue that warrants bringing my car to a shop, as it has never left me stranded and is not 100% reproducible. Any thoughts on what could be causing this, or suggestions of other details to pay attention to would be greatly appreciated!