I have a 2004 Ram 3500, 4X4, automatic with a chip (came with the truck) set to middle position. I've added a PAC exhaust brake, and an Air Dog lift pump. Been getting 24MPG on the highway w/cruise control and no A/C.

Truck started running rough, then would clear up within a few miles. I added CRC Bio-Con when I filled up, and it ran fine for three days. When it started, it ran rougher than before, and stalled twice. Drained and replaced the fuel filter with a Hann filter from Amsoil. Ran good for a week. When the tank was low, I replaced the filter. Original filter was black, replacement filter was brown after one tank.

Truck runs smooth as silk in the morning, and ran really bad in the afternoon. I live in south Florida, and the suns been beating on the truck all day.

I've been working on gasoline engines since 1964, and don't have a lot of trouble with them. This diesel has me yelling at the cat! Does anyone have any suggestions? Last shop I talked to said I must have a fuel problem....