I have a 1992 F150 inline 6 4x4 that has been a great truck for the past 2 years. Over the past couple of weeks, it's developed a problem when I go to start it. It starts right up then bogs down for 3 to 4 seconds and then runs just fine. It does this every time I start it too, doesn't matter how long it's been sitting. It also does this on both tanks, so I doubt that it's the fuel filters. Any ideas?