What we have here, is failure to communicate.
07-14-2016, 08:12 PM
#1
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Join Date: May 2012
Location: Lost in the wilds of Virginia
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Year: 1998 Classic (I'll get it running soon....) and 02 Grand
Model: Cherokee (XJ)
Engine: 4.0
What we have here, is failure to communicate.
My failure to communicate.
See, my son had done an O2 sensor with me on my pickup, so I knew he didn't need my help doing it on the Jeep. So I just asked him to replace it, and he reported that he did. He does good work, so I didn't question what he'd done.
But it didn't help, and I have been chasing this bad running problem for a year or so now.
To add to my confusion, along the way I've had a PCM die, then its replacement died after a week, then the distributor bearings wore out enough that the distributor wiped out my cam sensor, then the non-OEM cam sensor that came with the new distributor died an early death. (Gave me an intermittent no-start.)
Oh, and I found my fuel pump was intermittent, so I put a new Bosch in it.
Nothing cured my problem. At times it would run okay, but then it would go stupidly rich (5 MPG!) and buck and stumble and generally act like a spoiled child, and it's been getting worse.
My pickup has only one O2 sensor. My son didn't realize that the Jeep has two, and I never mentioned it.
As we were going over things a few days ago, he mentioned that while tracing wires he had noticed a second O2 sensor.
Turns out he had replaced the one after the cat.
All this time I've been troubleshooting based on the assumption that a new O2 sensor had not solved the problem.
He put the new one in the right place this morning, and my 50+ mile commute was smooth sailing both ways.
So, did someone say something about the meaning of, "assume"?
See, my son had done an O2 sensor with me on my pickup, so I knew he didn't need my help doing it on the Jeep. So I just asked him to replace it, and he reported that he did. He does good work, so I didn't question what he'd done.
But it didn't help, and I have been chasing this bad running problem for a year or so now.
To add to my confusion, along the way I've had a PCM die, then its replacement died after a week, then the distributor bearings wore out enough that the distributor wiped out my cam sensor, then the non-OEM cam sensor that came with the new distributor died an early death. (Gave me an intermittent no-start.)
Oh, and I found my fuel pump was intermittent, so I put a new Bosch in it.
Nothing cured my problem. At times it would run okay, but then it would go stupidly rich (5 MPG!) and buck and stumble and generally act like a spoiled child, and it's been getting worse.
My pickup has only one O2 sensor. My son didn't realize that the Jeep has two, and I never mentioned it.
As we were going over things a few days ago, he mentioned that while tracing wires he had noticed a second O2 sensor.
Turns out he had replaced the one after the cat.
All this time I've been troubleshooting based on the assumption that a new O2 sensor had not solved the problem.
He put the new one in the right place this morning, and my 50+ mile commute was smooth sailing both ways.
So, did someone say something about the meaning of, "assume"?
07-15-2016, 08:30 AM
#7
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Join Date: Aug 2011
Location: Prescott, Az
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
What a story.....
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