My Honda prelude wont start in the afternoon sun.?

my 94 honda prelude starts and runs just fine in the cool morning hours. in the afternoon it dont like to start but when it does it runs fine. This started a few years back and was kinda rare when it did it but now it does it everyday it seems. I noticed that when it does this, with the key in the run position the 'D' indicator light flashes. I'm lost and any suggestions would help thanks