So I decided to change my fuel filter today. Thought it might be a little clogged because when I accelerate onto the freeway it will miss/stumble for a quick second occasionally. It's a 5 speed manual and it only occurs in 4th/5th under acceleration, and a little load. So i changed filter, then tryed to prime the system, but i could never get any fuel to come through the air bleed cap on top of the filter. Tried cranking it 7-8 times w/ 2 minutes rest between but nothing. Took the filter out to try all over again, and noticed a good amount of sediment in the filter housing. So I called the chevy dealer asking for some advice. Couldn't really help me out, just told me that if I need a new PMD or pump they will only replace it under warranty if the fuel filter is clean and the fuel system flushed. Which cost 450$. But could save me $2000. This seems strange becasue the truck ran great except for an occasional stumble. Maybe i should have left the filter alone. Either way looks like in gonna be spending some bucks, anyone got advice as to what I should do? Now the trucks just sitting outside, and I need the dang thing running! It's a 98 6.5L 5 speed w/ 116,000 miles. Any the original engine was replaced at 60,000 miles.