94 Explorer 4.0 Auto - Problem started last summer and seems to only occur when the outside temp goes up. Had no problems during the late fall and throughout the winter. Vehicle will start in the morn? oh it will crank and turn over but it wont start. and after 20 sometimes 40 min of trying to start it, and then waiting, it will start. i have replaced the gas filter, and that helped last year. but now i am stumped. can you help me?

 

Get a fuel pressure gauge and make sure that you have enough pressure at the fuel rail. Make sure all of your ground connections are good.