Have them check/clean/secure the fuel pump ground. There's been issues with that.Having the same problem on my 2012 Elantra. Car will crank (as in the starter is trying to turn the engine over) but the car will not start. It sounds like there just isn't any fuel getting to the engine. Then the next day it starts right up. Car is at dealer now, but they can't reproduce it. If it matters, the problem started one night after a rain.