My 91 accord cranks very well but won't start when parked out in very hot sun for hours. Otherwise it starts right up under all other conditions. I replaced the main relay with no change! I'm out of other idears

 

I have seen lots of bad distributors that failed because of the heat.
Start perfectly when COLD but if you shut the car off after 10 - 15 minutes, the engine will not re-start.

Good luck. Please let us know if this fixes the problem.

HJ

 

Ok thanks ! I will replace the entire distributor

 

Ok I replaced the entire distributor . Unfortunately it made no difference at all.
so i'm still looking for idears.

 

Just picking at straws here but check the fuel filter and fuel pump.

 

When I throw water on the engine and leave it for a couple of minutes to cool -the engine starts