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I have a 1999 durango with 107,000 miles on it, I have replaced the wires,plugs and cap on it last year. Here is the problem, I can start the vehicle and drive it around and it runs perfect but when I park the vehicle after 4 hours it will crank but not start. I will leave the vehicle overnite and in the morning it will crank right over without sputtering and run like a champ. I have noticed that when I park it after 1 to 2 hours it will start, its after 3 hours plus it will not, I have tried after 7 hours and it will not also start but in the morning it runs great. I was also told that when the vehicle is cranking you can hear the fuel pump turning on
but I have not checked for spark yet. What could it be?