At night when the weather is cooler my engine idles under 1000rpms and runs fine. But during the day when the temperature is warmer my engine idles around 500rpms for a few minutes then starts idles at 200-300rpms and stalls out most of the time. I am going to change the fuel filter out and see if that's it. I was going to idle the car up using that idler screw but I'm not sure were it's at. Should I change my IAC valve? Any opinions, thanks.