I have a 2002 Caravan 3.3 with 120,000 miles. When I try to start it after sitting for twenty minutes or longer it won't start. If I turn the key to the off position and then back on several times then it will act like it wants to run but just won't start. If I keep turning the key off and then to start position several more times it will finally start. Once running there is no problems at all, plenty of power and no missing. The battery and starter are good and the engine turns at the right speed. I can hear the fuel pump start when the key is turned on and I checked and have good spark at the plugs. I think it's in the fuel system but I am not sure. Dose anyone know if this model has a check valve on the fuel line or does the fuel pressure regulator do the same job as a check valve? Any help would be greatly appreciated.