2000 Cherokee power problem

2000 Cherokee with a 4 liter and 133,000 miles. Okay, SOMETIMES when you take off it wants to sputter and buck and not take off. When you back off of the accelerator, it acts like it wants to go, so you step into it again and it again falls on its face. Then when it takes off, usually after about 5 seconds, it runs great and does run great most of the time. It just started getting a little worse and acting up alittle more often.

Most of the time it runs fine, but it has these spasms that I need to track down.

I've replaced the fuel pump and both screens, the throttle positioning sensor and have a crank positioning sensor and cam positioning sensor coming.

Any thoughts?? I'm just shooting in the dark. It's not throwing any codes or anything.

Thanks in advance.

Do these things have a MAF sensor??

A set of plugs might help. Your 2000 is distributorless, right?

I found out they don't have a MAF sensor, but they do have a MAP sensor. I pulled the MAP and thought even though it looked clean, I would spray some MAF sensor cleaner in it. After I did so, it wouldn't start at all! After setting all night I tried it again and got it to run, but it wouldn't keep running. Finally, it threw a code 1296 (cam positioning sensor) and a code 0340 (multiple misfires). I changed out the Cam sensor and it started for a moment and died.

I kept thinking about the MAP and decided to swap it out. The Jeep is now running like a champ. Hopefully, that was the problem. I also ordered a crank sensor, but it looks like I get to send it back. I'm gonna drive the hell out of it this week-end and see if it's gonna be okay or not.

Thanks for the suggestion though, that still probably wouldn't hurt.

T

Good call...sorry about the quick spark plug comment, there are a LOT of folks that don't replace their plugs ever.

Good catch on the cam position sensor. The 4.0 often has a problem with either that or the crank position sensor going.