Its a 92 Accord. When it sits out in the heat for a while it wont start. It turns over but wont start. After the sun goes down and it cools off it will start right up and run fine. What could the problem be?

 

Sounds like main relay. Next time it won't start listen to hear if the fuel pump is priming. If not I'd say that is your problem.

 

SpoonFedcrx is smart, that's the problem. The Relay is a little black or brown box located under the steering column, on the wall by the driver left foot. Slowly turn the key and you'll hear a Hmmm sound then a click. This is the main relay that control fuel. A common problem for older honda's. If you know how to solder, take the box out and check for cold solder joint.........................

 

Main Relay

 

Yup dude MAIN RELAY!! I had the same problem on my acura vigor. **** was like a vampire only at night. At least I could still go out to the clubs, but when your car can't start to get to work you have no money to go to clubs so I was screwed.

I went to Radioshack, bought a soldering gun, solder, solder braid (to remove solder), and some solder (make sure it's for electrical components). Total cost: $20 if not a little less.

Locate, Remove, Main relay.

Remove all the solder on the main relay and solder on new solder. If you have trouble removing solder just use some solder and solder over the existing solder.

Install back in car but don't attach main relay to the frame of the car. Zip tie it to the wires and you'll be set.

The main relay gets hot because the car is in the sun, the main relay is attached to a metal bracket on some cars. That metal bracket is attached to the car.
Car gets hot, transfers to metal bracket, transfers to main relay, theres your problem. Turn on the car and voila problem fixed.

for the most part you don't need to buy another main relay. I did this on 2 cars and it worked flawlessly.