alopeks
NAXJA Forum User
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- D/FW Metromess
Sorry in advance for the novel...
1999 XJ Sport, 4x4, 4.0, auto, 176K
Purchased in November, from a dealership in North Texas. Jeep was last owned by one of the Service Techs there, and was his teenage daughter's. He told me about a couple outer minor things, but mentioned nothing about any engine issues.
Noticed the idle a little rough about 2 weeks ago, and suspected vacuum leak or O2 sensor issue based on previous 99 XJ. Couldn't find leak anywhere, and sensors both checked out. Hadn't misfired or popped a CEL yet, so just tried to be careful. Few days later the CEL, and AutoZone pulled the code as P0455 - Large EVAP leak. Think I tracked down the source, but not sure, and it hasn't stopped the idle issue.
Later I started getting the misfire, VERY intermittently. Usually happened under hard load/acceleration, but still rarely. Vast majority of the time it didn't stumble at all. Threw another code, this time P0303 - Cylinder 3 Misfire Detected. I've read about the common vapor lock issue, which I never experienced in my old XJ, but I don't know if that one had been serviced/heat shield installed by previous owner. Doesn't look like there's heat shield on mine now. Question is, the misfire issue isn't necessarily following heat soak condition of the vapor lock issue. What I've read online indicates that this should happen more consistently based on short trips/warm engine starts.
AutoZone's system (I know, I know...) said most ASE mechanics would recommend checking crank position sensor. Looks like might a replacement based on connector style, but seems like the issue would be far more consistent if that was the problem, right?
I found a description of TSB 180100 that says there's a false code of misfires and EVAP leak, but I can't read the full text without buying it from some 3rd party source. I'd like to avoid that, since I can barely afford to keep gas in it at the moment...
Also, anyone know if Jeep will still install a heat shield, if that's the issue?
Again, sorry for the novel...
-alopeks
1999 XJ Sport, 4x4, 4.0, auto, 176K
Purchased in November, from a dealership in North Texas. Jeep was last owned by one of the Service Techs there, and was his teenage daughter's. He told me about a couple outer minor things, but mentioned nothing about any engine issues.
Noticed the idle a little rough about 2 weeks ago, and suspected vacuum leak or O2 sensor issue based on previous 99 XJ. Couldn't find leak anywhere, and sensors both checked out. Hadn't misfired or popped a CEL yet, so just tried to be careful. Few days later the CEL, and AutoZone pulled the code as P0455 - Large EVAP leak. Think I tracked down the source, but not sure, and it hasn't stopped the idle issue.
Later I started getting the misfire, VERY intermittently. Usually happened under hard load/acceleration, but still rarely. Vast majority of the time it didn't stumble at all. Threw another code, this time P0303 - Cylinder 3 Misfire Detected. I've read about the common vapor lock issue, which I never experienced in my old XJ, but I don't know if that one had been serviced/heat shield installed by previous owner. Doesn't look like there's heat shield on mine now. Question is, the misfire issue isn't necessarily following heat soak condition of the vapor lock issue. What I've read online indicates that this should happen more consistently based on short trips/warm engine starts.
AutoZone's system (I know, I know...) said most ASE mechanics would recommend checking crank position sensor. Looks like might a replacement based on connector style, but seems like the issue would be far more consistent if that was the problem, right?
I found a description of TSB 180100 that says there's a false code of misfires and EVAP leak, but I can't read the full text without buying it from some 3rd party source. I'd like to avoid that, since I can barely afford to keep gas in it at the moment...
Also, anyone know if Jeep will still install a heat shield, if that's the issue?
Again, sorry for the novel...
-alopeks