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Have to wait a while to start car after driving

I have a 93 Mustang 2.3l 4cyl. I have replaced the coil packs, fuel filter, alternator, CCRM, crankshaft position sensor, battery and fuel pump are both good. The issue i am having is that sometimes after i drive my car to the store after work and then come back out after about 30 min sometimes it wont start unless i let it sit for about 2 hours. I have been told it could be vapor lock, blown head gasket, or leaking fuel injectors. Also the car shakes a little while idling and after i turn off my car i smell a hint of gasoline. As for the head gasket i dont have white smoke out of my tailpipe and havent noticed water coming from my tailpipe. When i check the coolant it is green, doesnt look like it has mixed with oil. there is a muddy substance under the radiator cap, but i am going to have it flushed.

You may need to leave your car for a few days at a shop. They can start it up, let it run to “hot”, then shut it off. Eventually they should be able to get it not to start, at which point they can diagnose the problem stright away.

If I had to guess, I’d say this is an electrical problem. A relay sticking perhaps. But with a 93, it could be a lot of things. If the car is scheduled for any routine maintenance, like a tune-up, now might be a good time to do it.

We had a similar problem with a newer ford, I had the wife stop by every time she passed the dealership, ended up in failure mode need a new fuel pump was the solution. Your car appears earlier than the experience I had, but if you can get it to fail at a shop that would be ideal

I would check for a fuel pressure loss; maybe due to a leaking fuel pressure regulator.
A leak in this area can cause a flooded condition. After sitting for a few hours any gasoline that has leaked will have evaporated and the flooded condition has gone away.

This could also cause a rough idle from excessive richness.

Try pulling the vacuum line loose from the fuel pressure regulator and note if there’s any gasoline in it, whether a gas smell is present, etc. There should be none.

When attempting to restart the hot engine do you press the accelerator?

I would suggest that you clean the throttle and idle air control valve and if that gives no improvement try blocking off the EGR valve temporarily.