Car will crank but not start

I have a 90 Accord EX Coupe. On really hot mornings and afternoons the car will crank but not start up...if I open all the doors, sunroof and hood and let it sit for 10-15 mins it will fianlly start up. What is the problem. I do not see any loose wires or cables. Check all the plug wires and battery is strong.

HELP!!

its probably your main relay. this tends to go bad on cord from 90- 97 the relay controls the fuel, therfore it will crank but not start.

Where is it located? Is it inthe engine bay?? What makes them go bad???