Car stalling, No start after pulling over.
 

Hi guys the past two days it has been hot 95+ and my turbo miata will crank and drive fine but after a 30 min or more trip it starts to sputter as if its out of gas. When i pull over to want crank back up until it has sat for 20 mins or so. also i have noticed that while the car was sitting for a day or 2 at a time it starts funny. It cranks to soon and sputters until it even back out. any suggestions on what it could be. Btw it has a new fuel pump, supra injectors, and a new fuel filter.

Sounds like something sensor related. I had a similar issue with a Chevy pickup, it'd run fine for 5 minutes until it heated up, and then would bog down and eventually shut off. Coolant sensor was dead, sending a -40* signal constantly. It was running way to rich to keep running once warm.

This was an '88 Chevy, not a Miata, so I'm not sure what influence the stock sensor has on the ECU's fuel map, but it's worth a look. It would explain why it starts back up after 20 minutes.

I also haven't heard too many problems with them, giving me the assumption that they're fairly reliable. I'd double check the wiring in the back of the head before replacing the sensor.

What EMS?

i have a wideband and it shows 14-15 afr the whole time until it just goes from normal to sputtering. im thinking maybe cps?

its factory with the voodoo box only having effect under boost

14-15 even under boost? You have other problems then as well.

lol no not under boost im talking crusing boost afrs maybe 12.5.12.9

What fuel pump? Stock or aftermarket?