Love the 4.0, but....

[Redneckryder]

This engine has issues. Biggest one is an intermittent hesitation/loading up feeling. Take off, and it feels like you are hauling a huge trailer behind you. Get to about 2000-2300 rpm, and whatever it is breaks free, and it goes like a bat outta hell. If it did it all the time, I wouldn't be so confused, but it will go a couple days running fine, then this will happen for a week straight, then it will be fine for a day then run crappy for a day......you get the point. Usually runs good when you first start it up, but this thing that happens can start as soon as 45 a mile down the road, or 3 hours into a drive. I replaced the plugs and wires, didn't do anything. So, now I appeal to the more knowledgeable guru's on this site. Anyone have a clue? I cannot afford to just throw money at it hoping it goes away.....

 

[papasmurfor9]

I would check fuel pressure....could related to a bad fuel pump or pressure regulators....or could be a vacuum leak related like a bad hose or intake gasket leak.