Im having an on and off issue with how my car idles, if im at a stop in gear the car would stutter and now and than the rpm would slightly drop and than catch back up, it idles where it should at around 750ish give or take with the ac and headlights on, and maybe about 675is give a take with no accessories on. The weird thing is, it only does it when extremely hot outside! As in high 80 degress and hotter, the last 2 weeks has been a hot spell for us with temps nearly over 100 degrees every single day, it just cooled off to the low 80s and 70s the last 2 days and my car has been idling perfect with no stutters! So it only does this when its really hot outside, im thinking its the fuel pump because i can hear it hum louder than normal, what can fail on these cars that would cause this weird idle issue only when its very hot out? Fuel pump seems the be the likely suspect but im open to ideas. Car has no driveabillity issues.

 

I have this same issue minus the fuel pump humming. It stutters really quick then runs normal.. Its a random occurrence in my case.. I have posted about this before, and someone told me that it was the Idle air control sensor. I haven't changed mine since it only does this maybe once every two to three weeks.

 

I updated my other thread, issue was a failing coil on cylinder 4. changed the coil out and its running perfect with no more stumbling or misfires!