John,
Before you do ANYTHING... ... . CHANGE YOUR FUEL FILTER!!!!! I just had the nearly identical problem. Truck was sluggish for last 3-4 weeks, passed it off as ULSD characteristic as Flying J switched over about mid Oct. Last night, leaving work I started it up, put it in drive, went 2-3 feet and the thing cut off- then went on like nothing happened.

On the phone with local Dodge dealer diesel tech (Kirkwood Dodge, DE. that was VERY helpful over the phone!!), my brother-in-law, and here on TDR, searching for answers, consensus was the fuel filter. I figured, just wasting my time, but what the heck, 20 bucks beats the alternative. Pulled it out, it was dark as night!!! Started the truck, I drove it like I stole it!!! No hesitation, no miss, cough, gag, snort, p*ss, moan, NOTHING!!! So, with the help of family, a stranger, and alot of friends here, I'm back on the road. I'm going to change the filter again in 2 months just to see what it looks like.

Bobby Plummer