Just wanted to say thank you to this forum. I signed up yesterday and was able to solve my problem with advice gleaned from this forum.
I have a 2000 XJ 4.0 with 198K (best vehicle I have ever owned...just wish I had a 4x4). Friday morning my Jeep had a very rough idle and misfire with acceleration. The CEL was intermittent and my scanner would not retrieve the code.
So I followed the basics ya'll recommend. New set of Champions (I had Bosch +4's, the #6 plug was slightly carbon fouled), checked the voltage on my coil pack...no change.
My 2 best friends and my mother have 00-01 XJ's, so we have been through some of the common stuff. I pro-actively changed my CPS and TPS while they were still good so that I would have good ones sitting on the shelf. I threw in the spares...no change.
I think the problem was the #6 injector, even though it was not throwing a code. I removed and cleaned the injectors and swapped the #6 and #2 injector and the problem went away. I figured if the #2 plug fouled, I would have the problem figured out. Changed the oil too in case the injector was leaking into the cylinder.
But seriously, the info on this site was very helpful, thank you. My next step was to buy a fuel pressure tester. Gonna do that soon and have it on the shelf because it sounds like it is mandatory to diagnose problems like I have.
Mods and repairs to my Jeep: Aussie locker, dynomax muffler, electric fan, 2 row radiator (all metal), rear main seal and oil pump, new headliner, new seat foam and upholstery....basically just my daily driver that I maintain and enjoy. I'll never understand why they discontinued the XJ or the 4.0.
I have a 2000 XJ 4.0 with 198K (best vehicle I have ever owned...just wish I had a 4x4). Friday morning my Jeep had a very rough idle and misfire with acceleration. The CEL was intermittent and my scanner would not retrieve the code.
So I followed the basics ya'll recommend. New set of Champions (I had Bosch +4's, the #6 plug was slightly carbon fouled), checked the voltage on my coil pack...no change.
My 2 best friends and my mother have 00-01 XJ's, so we have been through some of the common stuff. I pro-actively changed my CPS and TPS while they were still good so that I would have good ones sitting on the shelf. I threw in the spares...no change.
I think the problem was the #6 injector, even though it was not throwing a code. I removed and cleaned the injectors and swapped the #6 and #2 injector and the problem went away. I figured if the #2 plug fouled, I would have the problem figured out. Changed the oil too in case the injector was leaking into the cylinder.
But seriously, the info on this site was very helpful, thank you. My next step was to buy a fuel pressure tester. Gonna do that soon and have it on the shelf because it sounds like it is mandatory to diagnose problems like I have.
Mods and repairs to my Jeep: Aussie locker, dynomax muffler, electric fan, 2 row radiator (all metal), rear main seal and oil pump, new headliner, new seat foam and upholstery....basically just my daily driver that I maintain and enjoy. I'll never understand why they discontinued the XJ or the 4.0.