Rough Start in Hot Weather on 2006 Toyota Corolla

I have taken my car to mechanic and dealer and both cannot find anything mechanically wrong with it does not throw codes. But is rough to start when I drive at least 15 miles in hot weather and let it sit for couple hours. It starts right up in the morning though. I have spent so much money on repairs lately I am at a loss Please HELP!

Asked by for the 2006 Toyota Corolla
Time to find another car.
1 more answer , 2 more comments
Let a mechanic keep the car so he can see what the problem is. He can let the engine idle awhile, shut off the car and then do some testing while it is acting up!
I already have and have no explanation.
No more suggestions, sorry.