The motor idles between 2500 and 3000 when outside temperatures are high

My 2013 Kia Sorento wont start... since it simply shut down on night while my boyfriend was driving I figured it had to be the alternator so I replaced it and it worked fine for 2 days and then did it… 

Want crank in the morning and have to hold you gas pedal down and turn a long time for it to start and white smoke come out of it,and clear up in a little while. And it cranks all day long till the ne… 

Occasionally revs limited to 3000. Stop and switch off for one minute and restart Return to normal. All new pumps, injectors, pressure regulator and sensor, clean tank,air filter and fuel cap not fixe… 

Back doors wont lock but the front will