My Jeep has developed an intermittent dead miss similar to the engine is turned off and restarted.

1998 JEEP CHEROKEE
114,000 MILES
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JS51679
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1998 Jeep Wrangler 114,000 miles, in good condition - I have an intermittent problem where a dead miss occurs as it's going down the highway. Happened first time about four weeks ago. Happened again ladst week; the tack goes to zero while driving and then as the ingition/ power resumes it continues to run as though nothing happened. I pulled over and the vehicle died with "check engine" light on. I turned the ignition switch off (3 - 5 seconds) and then back on to start. It started and ran normal. Continued to run normal through the weekend. I had the codes checked, it gave a "cam & crank sensor" error. Checked the timing, appeared correct (9 - 11BTDC). Observed all the spark plug wires are in good working order. I'm thinking possibly the prob might be in the ignition switch, however, this doesn't really match the code being provided. Suggestions??
Feb 6, 2012 at 4:11 PM
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RIVERMIKERAT
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Check the wiring to and from the cam and cranks sensors. Make sure they're both properly set and gapped. Not loose. No loose connectors. If they haven;t been changed in 144K miles, they could be failing.
Feb 6, 2012 at 6:53 PM
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JS51679
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Thank you!
Feb 6, 2012 at 7:55 PM
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RIVERMIKERAT
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My pleasure. Let us know what you find.
Feb 6, 2012 at 8:23 PM
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JS51679
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This is in follow-up to my 1998 Jeep Wrangler intermittent ignition problem. Replaced the crankshaft sensor. Runs good. However, yesterday at high speed (75 - 85 mph), I received another check engine light. Three codes, one each for spark plug misfire on 3 of 6 cylinders. The plugs and wires were replaced last June (2011). Checked the wires to make sure they are assigned to the correct cylinders (and they are). Again, it runs good, no indication of a miss while going down the highway. I cleared the codes, ran it this morning (<75 mph) and no codes developed. Maybe cap or rotor, wouldn't think its the coil, it runnig too good. Suggestions? Thanks for your assistance, Jesse
Feb 8, 2012 at 7:58 PM
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RIVERMIKERAT
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Dumb question, but you cleared codes after installing the crank sensor and before going for the test drive, right?

Check the underside of the cap for arcing and tracing.
Feb 9, 2012 at 4:25 AM
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JS51679
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Autozone read the initial code (P0320 CKP); the counter person told me he would clear the code. However, I'm not 100% sure since I didn't watch them. I know the second set of codes (P030x multipe misfires) were cleared because I watched the Autozone person do it. Since then, I've drove it the last two days and so far no codes have reappeared. I have held my speed to below 80 mph. I did an internet search on "1998 Jeep misfire codes." There's allot of discussion about possible misfire code causes; other sensors, after-market vs. OE parts, dist caps, rotors and weak valve springs. Yet, there was one discussion thread that described exactly what I'm experiencing to include both codes (CKP & misfire) and contributing driving habits (higher speeds). Their solution: recheck the crankshaft position sensor (CKP) installation to make sure it is seated properly in relation to the flywheel. They stated that while the sensor only moved an additional 1/32", it was enough to stop the misfire codes from reoccurring. So far, it appears the CKP sensor was the prob for the initial code (no more random dead misses or engine dying). The installation of the CKP sensor is such that it's difficult for one person to apply pressure on the CKP sensor while tightening the retaining bolt. I'll either get someone to assist or figure out how to wedge something against the sensor to insure it is seated all of the way down as I tightening the bolt. (I know there has to be an air gap between the sensor end and F/W. It came with a paper spacer to insure proper spacing.) I have a tendenancy to overlook the obvious. Worth a shot before I pursue some of the other suggestions ($$$$). Please let me know if you see something that I'm missing...... Obviously, I'm weak at the diagnostics. Like most, I'm a parts changer.
Feb 9, 2012 at 2:49 PM
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JS51679
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Good suggestion on visually checking the dist cap for arcing and tracing. Thank you!! This will provide an indication of whether the cap and rotor are functioning properly. I'll check it this afternoon after work.
Feb 9, 2012 at 2:58 PM
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RIVERMIKERAT
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My pleasure. It sounds like you've gotten the obvious bases covered quite well. Nothing pops into mind that you haven't tried yet.
Feb 9, 2012 at 11:59 PM
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JS51679
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Greetings- Just to follow-up, our collaborative efforts appears to have resolved Jeep Wrangler issue. So far, no more codes through the weekend. Thanks again for your help. Jesse
Feb 13, 2012 at 5:04 PM
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RIVERMIKERAT
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My pleasure. Be sure to tell your friends about us.

Thread closing.
Feb 13, 2012 at 7:22 PM
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