So way back I had a 1st gen RX7, fuel injected, and everyone said it was a rotary problem of being flooded after a short start. WELL it's either a mazda issue or fuel injection in general... cause they haven't figured it out yet.
A few months back I had moved the car in the driveway and then it sat overnight - wouldn't start the next day. So I used another vehicle, tried reading codes and I don't recall what else. After sitting for another day or two is when I think I tried again and flooring it actually got it to sputter and it ended up starting.
Well this past weekend I changed the oil, afterwards I started it for a minute to verify no leaks and then let it sit overnight.
The next day it would not start, just cranks with no apparent sputtering or anything. Tried hitting the gas and it sputtered but not even close to starting. This time I assumed it was flooded, pulled the fuel pump fuse near the battery and the engine cranked, caught, then died with no fuel. Put the fuse back in and it started with a little roughness & didn't respond at all to the throttle. After ~20 sec of slow / wandering idle I turned it off again. Restarting again it idled fine, responded to throttle & it had the check engine light on. Though since it was running ok I just went for a drive.
After ~3 ignition cycles the check engine light went off, it had no issues starting any other time over the next few days.

So it looks like i'll have to put in a fuel cutoff switch to give an easy out to this issue when it happens again. I'm curious if anyone else has had this problem. But in the mean time - beware not to run the engine run a bit before shutting it off overnight.

 

I have this exact problem and don't know what to do to fix it. I have a 2012 Mazda 3 sedan. Same exact sequence; I start the car to move it forward a couple of spaces on the street, shut it off and let it sit overnight or a day the last time. Doesn't start the next morning/day. Open the hood, let it sit for a bit, push the pedal to the floor and it turns over sputtering. I lightly touch the gas to get it up to idle speed and it runs. No codes (FIXD Reader) or check engine light. Same solution you came up with. Don't shut off right away. Wait for the idle to drop and the car starts and runs fine at that point. I am going to still research further but if you find out what it is, please let me know. What do you think about a sensor or a regulator. I have to look it up still. Could whatever it has be going bad?

I changed the plugs, cleaned the mass airflow sensor and something else last time, maybe a PVC valve. It's definitely a flooding problem though.

 

I've had fine luck just gunning the engine just before a cold shut off. I think about 4k rpms has enough momentum to let the engine blow through any fuel after ignition off, which leaves the cylinders clean enough to start normally later.

 

I have this issue. Same vehicle. Ever figure this out?