Hey there,

I have a 2001 XJ classic with about 103,000 on the odometer. I am the second owner and have only had it for about 5000 miles. It started to idle pretty rough and has a loss of power on acceleration. I am not super familiar with these 4.0l engines but I tried the CPS, the coil pack, and fuel injectors. The problem has not gone away, and the PCM is throwing cylinder misfire codes. Three at first, cylinders 2,3 and 5. Since this work it has just thrown a code for cylinder 6. I also changed the oil and put some sea foam in the fuel. Not sure where else to go from here and was hoping for some suggestions on what to look at next. Thanks

 

1. Welcome to the forum.
2. Stop throwing parts at it.
3. Test, then replace.

Have you tested the fuel pressure? IIRC, you need about 55 pounds. Could also be the cam sensor. It throws symptoms very much like the CPS, but this really isn't the right set of symptoms for either one. Could be, but they are not the prime suspects. Then there's the obvious - how about the plugs?

Make sure your grounds are all in very good shape. The ECM ground especially.