Originally Posted by Tomguy

Dripping injectors, including cold start valve. Air intake sensor.

Those are two things I'd check. At 104°F (40°C) the air intake sensor should read 150 Ohms. It should read 210 Ohms at 30°C / 86°F. A huge difference in temp there for only 60 ohms. If you want to experiment, put a straight resistor in there of 150 ohms on the hotter days, IF the sensor is reading over 150 on a hot day like that. If unplugging the sensor while idling does not make a huge difference in your idle the wires may be broken in the plug or harness to the air intake sensor. That'd have you chasing your tail for ages.