Honda Civic has trouble starting after sitting in the sun

I have a 1.5L, 4 cylinder, manual 1993 Honda Civic 142K miles that runs great, however, if it sits for a few hours in direct sunlight on a hot day, it has trouble starting. I know this sounds wierd, but if I park in the shade, I don't have the problem. For example, yesterday I parked my car in the shade, but as the day progressed, the shade moved. After my car had been sitting in direct sunlight for a few hours, I tried starting it in the heat of the day, and the car only turns over without starting. I left it and came back in the evening and the car started on the first try as if it had no problems. I experience no problems in the winter or if I park in the shade in the summer; however, if the sun gets a chance to beat down on it on a hot day, it may not start or it may take a few minutes of trying till it starts. The only think I know that has been changed is the previous owner installed a cold air intake on the car. I'd appreciate any information someone may have in fixing this problem.