I am new to the forum(posted introduction in "Other" category), but I am having some very frustrating problems with my truck. Towing a trailer on my way to Michigan the truck started bucking around 2200 rpm. I was climbing a grade up to Chiraco Summit and near the top of the grade it started bucking/missing. I was barely able get up the off ramp and turn the truck around. On the way back home it smoothed out, but again started bucking/missing around 50 mph. Never had the truck in OD while towing, and cruise control was off. Dodge "techs" thought fuel filter. Changed filter, same problem, sometimes hard starts, esp. when the day was hot(I live in the desert). When truck was not under load no problem. Suspected lift pump, replaced the lift pump and installed FASS system. Ran great for a few hours(not towing or under load). This morning the truck started hard but ran fine. Went for coffee.. A bit hard starting, then stalled, then ran great. Drove the interstate and at 50 mph it started bucking/missing/rough. I pulled off the freeway, let it sit for a few minutes and the truck started up and ran just fine home. I am at a loss, and really need to head out to Michigan soon. I have not had the truck under load(no trailer) since my first attempt up Chiraco Summit.
Any suggestions/advice you could offer would be much appreciated. I am praying it is not the fuel injection pump.

 

i'd look into an overflow valve (for the loss of power @55) and the fuel lines leading from the tank to the pump that might be leaking air into the system hence the hard cranking....

 

Sorry to say it sounds like the problem I was having, and yes 1800 bucks later it was the fuel pump. I don't have the power I had before so it isn't perfect but I can atleast tow now.