esms06
NAXJA Forum User
- Location
- havelock, NC
I was wondering if somebody here could help me diagnose this issue. I've been at it for a couple of months and have not come to a definite solution yet. I apologize in advance for the lengthy post. It is a 2001 XJ 4.0 Automatic.
The symptoms are as follows. Rough idle around 500 rpms, miss cylinder 1 2 3, codes P0171, P0131, P0137, Fouled out spark plugs cylinder 1 2 and 3, Black sut on tailpipe and when I step on it and last but not least HORRIBLE gas mileage.
Things I have done. Checked the crank position sensor, Tune up, Changed the all the spark plugs and 1000 miles later the first three spark plugs were completely fouled out. Changed both 1/1 and 1/2 oxygen sensors with OEM sensors. Switched the relay and fuse. Took the XJ to the Dealership and had them check the wiring to the oxygen sensors and they said they would need at least 2-3 more hours of diagnostic time and can't promise results. I checked all the vacuum lines, cylinder leak down test and compression test. Every turned out fine. Also did an intake manifold vacuum pressure test and that turned out fine. I also cleaned the IAC and the throttle body. The only things I could imagine being wrong is either the wiring to the 02 sensor or ground, those three injectors are stuck open, catalytic converter on that side being bad because the 02 sensor was ran bad for so long, unsuffiecient spark to those three cylinders or the worst an ECM.
I am very stumped and strapped for cash so I don't have money to throw at it. Anything else you recommend me doing? Forgot to mention I have tried reseting the computer and I have been checking the codes and voltage using a Snap-on Solus diagnostic tool. I hope you XJ gurus could help me out. This is my fourth and final XJ. Plan on taking it to the grave with me.
The symptoms are as follows. Rough idle around 500 rpms, miss cylinder 1 2 3, codes P0171, P0131, P0137, Fouled out spark plugs cylinder 1 2 and 3, Black sut on tailpipe and when I step on it and last but not least HORRIBLE gas mileage.
Things I have done. Checked the crank position sensor, Tune up, Changed the all the spark plugs and 1000 miles later the first three spark plugs were completely fouled out. Changed both 1/1 and 1/2 oxygen sensors with OEM sensors. Switched the relay and fuse. Took the XJ to the Dealership and had them check the wiring to the oxygen sensors and they said they would need at least 2-3 more hours of diagnostic time and can't promise results. I checked all the vacuum lines, cylinder leak down test and compression test. Every turned out fine. Also did an intake manifold vacuum pressure test and that turned out fine. I also cleaned the IAC and the throttle body. The only things I could imagine being wrong is either the wiring to the 02 sensor or ground, those three injectors are stuck open, catalytic converter on that side being bad because the 02 sensor was ran bad for so long, unsuffiecient spark to those three cylinders or the worst an ECM.
I am very stumped and strapped for cash so I don't have money to throw at it. Anything else you recommend me doing? Forgot to mention I have tried reseting the computer and I have been checking the codes and voltage using a Snap-on Solus diagnostic tool. I hope you XJ gurus could help me out. This is my fourth and final XJ. Plan on taking it to the grave with me.
