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What are the symptoms of a bad crank sensor

Old 12-01-2011, 11:59 AM
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If mine was backfireing I would check that inside the dist cap is clean & dry.

(sorry if that's been done!)
Old 12-01-2011, 05:17 PM
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Originally Posted by OllllO Isaac
Would the crankshaft position sensor cause the jeep to backfire while trying to start up??
Not on a Renix era Jeep. The OP's problem sounds like a lean condition caused by a weak/failing fuel pump. Check the fuel pressure.
Old 12-01-2011, 05:33 PM
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Not attempting to sound redundant, but just wanted to clarify. A bad cps can indeed cause bad idle? I have had bad idling problems in the winter, and over this past summer I had to replace the cps. In theory, that could have been a possibly solution to the bad idling?
Old 12-01-2011, 05:37 PM
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Originally Posted by stinsonbr
Not attempting to sound redundant, but just wanted to clarify. A bad cps can indeed cause bad idle? I have had bad idling problems in the winter, and over this past summer I had to replace the cps. In theory, that could have been a possibly solution to the bad idling?
What year is your Jeep?
Old 12-01-2011, 05:46 PM
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2000 Cherokee sport 4L
Old 12-01-2011, 06:35 PM
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Originally Posted by cruiser54
What year is your Jeep?
2000 Cherokee sport 4L
Old 02-06-2014, 04:28 PM
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Default 97 xj could this be my issue

I have a 97 xj 4.0 sport it was acting like it was out of time and would not run started tinkering and discovered some wires when i applied pressure it would run fine it was the wires leading to the crank sensor. So i replaced the wiring harness. Now it wont even run it will turn over and try to start but never start. Ive put it in time TDC by the marks on the gears distributor is new it has compression on all cylinders has spark into and out of distributor i am completely lost at this point it will turn over and backfire through the throttle body the plugs are gas soaked. I am in north georgia if anyone knows any jeep geniuses around the area itd be appreciated as would any advice.
Old 02-06-2014, 05:32 PM
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How strong is your spark? is it blue and snaps or is it yellow/orange? A weak spark may not be enough to light the mixture. Any chance the distributor is not in correctly? Sounds like the spark may not be at the right place at the right time (wet plugs).
Old 02-06-2014, 07:02 PM
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Hi Ryan. I was new to forums not so long ago. Here is a way to start. First go to > https://www.cherokeeforum.com/ The first (top) one is "OEM cherokee teck" I bookmarked that, (or favorites, if you are still stuck in exploiter)

Firefox is a way better browser. Then after clicking on "new thread" , explain your issue. We are generally a friendly place, but if you post " I poked on some wires", you are sort of asking for it. Were they the muffler bearing wires, or the ones to the roof rack?

This thread is years old, brush up on punctuation and be direct/complete with the description of your issue in your new thread, and you should be good to go. Best of luck! Map.
Old 06-06-2014, 11:15 PM
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I had the same thing in my 91 XJ, started good and when I would give it gas to move would buck and spit and just run like crap...turned out to be the bad fuel pump in the tank...replaced the fuel pump and all is good now....might give it a look see.
Old 07-02-2014, 07:31 AM
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I just replaced mine on a 2000 XJ 4.0L thanks to this great site and it runs beautifully. Symptoms were no spark, no fuel pressure. I was so tempted to change the fuel pump because it wasn't even priming with KOIO, but against my better judgement I replaced the CPS and it started right up. There are lots of videos that helped, but I found that using a wobble extension rather than a universal was much easier for 1 person to do the job. Removing the bracket that held the CPS connectors helped tremendously with visibility from the bottom. I almost dropped the drive shaft, but managed without it. Thanks again.
Old 07-12-2018, 08:03 AM
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I have a 99 Cherokee sport, and I have been chasing an idle issue for months. While the jeep is idling there is a slight skip and the tach jumps slightly. If you hold it at 2k rpms the skip is more pronounced. Also, while driving when the jeep shifts into od it jerks and seems to lose power for a split second. I have replaced all of the common ignition parts. Oh, and it used to stall in reverse if I gave it to much gas. Does anyone have the similar issue?
Old 07-12-2018, 02:19 PM
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Not to hijack this thread but I want to post what recently happened to my 1999 Limited w/ 180K miles. I've never had a "crank, no start" issue in the 6 years I've owned her but I did have to replace the crankshaft position sensor last year. The other morning I went to start it and she cranked but would not start (she usually starts with a second or two). First thing I did was come on here and do some research. I pulled the cap and noticed the connectors were heavily corroded (see pic). I went to my local Jeep dealer and purchased a new cap, rotor and distributor pickup coil and then to the local auto parts store and grabbed some Champion copper plugs to replace the NGK platinums that have been in there for at least 25K miles (I opted not to replace the Taylor wires and MSD ignition coil for reasons). Now, when I was at the dealer I reluctantly asked for a cam position sensor and was told '99s and below equipped with distributors do not have one. I was a bit confused because during my research I read quite a bit about replacing the cam position sensor to correct a "crank, no start" issue. I also read about a part called the stator but came to the conclusion that it was just another name for the cam position sensor. So I went home and replaced the parts, buttoned everything up but she still wouldn't start. I don't know why I did this but I disconnected the negative battery terminal for a few minutes and tried again. This time she started but ran rough for a few seconds but eventually smoothed out (she actually idled great). I started her up a few hours later and the next morning but when I went to go out later the next afternoon she would crank but not start. I disconnected the negative terminal, reconnected it and she started right up. I had a lot of errands to run today and was reluctant to drive her but so far she started right up within a second every time. I have no explanation as to why but I'm keeping my fingers crossed that I have no further issues.
Old 01-31-2022, 06:48 AM
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Originally Posted by 99chrokeesport
I have a 99 Cherokee sport, and I have been chasing an idle issue for months. While the jeep is idling there is a slight skip and the tach jumps slightly. If you hold it at 2k rpms the skip is more pronounced. Also, while driving when the jeep shifts into od it jerks and seems to lose power for a split second. I have replaced all of the common ignition parts. Oh, and it used to stall in reverse if I gave it to much gas. Does anyone have the similar issue?
Any luck figuring this problem out?
Old 08-21-2023, 03:35 PM
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wow this is the exact same problem im having i already changed the crank sensor and the cam sensor..kinda stuck

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