Hyundai Repair: 2004 Sonata hard to start at Hot Weather, fuel pressure gauge, fuel pressure regulator

Question
I have a 2004 Hyundai Sonata and I stay in Topical country. My car goes well in the morning when the weather is cool. However, I am getting hard time to start it when the weather is hot or after driving for some time.
Usually I need to start for 2 to 3 times during noon time when the weather is hot. Or after I drove for some time and leave the car off for half an hour then it getting hard to start. If I start immediately after I stop the engine, it can start up immediately. However, If I leave the car off for half an hour, then I am getting hard time to start it. Need to start for 2 or 3 time.

Please advise where goes wrong with my car.

Thanks.
Andy

Answer
You might start by installing a fuel pressure gauge, if you have one with the proper adaptor.  Based on your description, I suspect the fuel pressure is bleeding off through the fuel pressure regulator while the car is off.  If so, replace the fuel pressure regulator.