My 1999 is giving me problems after it sits over night or for a few days. It's not a cold start problem because here in Florida we do not get cold weather. It cranks fine but the way I get it to start is I put the key in the crank postion and try to start then keep shutting it off and try to start. You can hear the fuel pump go on and the pressure is 58lb, the pump was changed about 6 years ago. When it does start it runs rough till I drive it awhile. Acts like a fuel problem, I have never changed the injectors or the fuel pressure regulator it has 150000 on the clock. I have maintain it well changing stuff as it goes and it runs great other then this start problem. There are no codes. How do I check the fuel pressure regulator? Any ideas or areas I should check?