dies when hot outside?

[kewpie79]

I have a 2000 explorer with 75000 miles on it, stock engine. Whenever it is driven and it is over 90 outside, it will start to stutter and then just die. It won't start until the engine cools off. A new fuel filter has been put on, new relay for the fuel pump. I can hear the pump come on when turning the key, and there is no check engine light on. Is the fuel pump on the way out or could it be something else?

 

[mikeh44]

sounds like vapor lock

 

[kewpie79]

what causes vapor lock?

 

[budwich]

I would suggested that you find a way to get a fuel pressure reading during a "hot cycle". If I recall some of the posts, fuel pressure is regulated "computerly" as opposed to via a "hard regulator" in newer model... but I can't recall what years they started in.

 

[dynamite196]

Usually a plugged vacuum hose, when was the last time the pcv valve was changed?

 

[kewpie79]

changed the pcv one week ago