1980 JEEP CJ5 ENGINE KEEPS RUNNING AFTER KEY IS TURNED OFF

  • Tiny
  • Raddad
  • 1980 JEEP CJ5

Electrical problem
1980 Jeep CJ5 4 cyl Four Wheel Drive Manual 150000 miles

1980 Jeep CJ5, 151 4cyl GM Iron Duke engine.
Starts fine, but keeps running after the key is turned off. Replaced the key switch a year ago, just replaced the ignition switch yesterday, but that did not help. It is not pinging or running on, but continues to run normally even though the key is off and voltage meter shows not power.

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Thursday, August 20th, 2009 AT 1:01 PM

9 Replies

  • Tiny
  • ImpalaSS
  • EXPERT
  • 3,148 POSTS

Hello -

Well, the bad thing is our manuals don't have any info on your vehicle. The manufacture didn't release that.
However, please check the linkage between the key switch and ignition switch. It may be out of adjustment.

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Thursday, August 20th, 2009 AT 9:44 PM
  • Tiny
  • Raddad
  • MEMBER

I have a couple shop manuals for the vehicle but they didn't address the problem - that's why I contacted you. Other forums have since indicated it may be a defective diode between the alternator and coil, causing feedback (or backfeed), so I will pursue that.
Can't say I'm especially impressed with your response.

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Friday, August 21st, 2009 AT 7:52 AM
  • Tiny
  • ImpalaSS
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Hello -

I apologize the answer didn't meet your expectations. I have attached the pic of shop manual we refer to. As it says, "Information for this vehicle is not available." Which from what you stated.......your manuals don't provide the answer either.


http://www.2carpros.com/forum/automotive_pictures/248015_Jeep_1.jpg



There are various vehicles we deal with that the manufacture doesn't release certain technical information. That is beyond our control. In this case the manufacture doesn't release ANY information on this vehicle.....not even the tire pressure.........

I wasn't trying to impress you with my reply, only assist you with your problem as we do many customers. I felt being honest with you letting you know that our manuals didn't have any info on your vehicle was the right thing to do. Yet at the same time offer some assistance to your problem.

I recently worked a similar problem with a vehicle; though that vehicle had plenty of information in our manual it too didn't address the linkage. However, the linkage was out slightly...........thus you turn the key..........the car continued to run, as yours. They adjusted the linkage and it worked fine.

Please let us know what you find out so the other readers may benefit from your information............

I will also refer your input to our supervisor so he too is advised of the situation.

Thanks and I hope you have a good weekend.

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Friday, August 21st, 2009 AT 9:10 PM
  • Tiny
  • Rasmataz
  • MEMBER

Run-on/Dieseling:

Let me ask you, How high is your curb idle? The throttle plate might not be closing completely to choke off the incoming air. There's a few that can cause your problem w/o a problem with ignition switch and key switch such as the following:

Engine could be overheating, Hot spots in the cylinders, vacuum leaks and ignition timing off.

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Friday, August 21st, 2009 AT 10:01 PM
  • Tiny
  • Raddad
  • MEMBER

Thanks to all - and excuse my frustration with the initial response. Though the problem is not run-on, it simply ignores the fact that the key is off. It happened after the vehicle was idle for a few weeks in high humidity. Getting a new diode trio for the alternator today, as I suspect the issue may be related to current feedback. I looked at the ignition switch linkage as I replaced the switch and it looks fine.

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Saturday, August 22nd, 2009 AT 9:28 AM
  • Tiny
  • ImpalaSS
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Hello -

Have you replaced the diode trio yet. Still have the same problem or is it repaired?

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Tuesday, August 25th, 2009 AT 9:34 PM
  • Tiny
  • Raddad
  • MEMBER

Well, yes, I did replace the diode trio, and it did solve the problem. However. Shortly after that, something began draining the battery whenever it sat idle for a few hours.
Could not find anything that was obviously pulling current, and when we tested for draw, by removing and touching the battery cables to the terminal and looking for sparks, nothing showed up. Finally replaced the alternator with a reman, and removed and cleaned all the ground wires. Seems to be fine now, providing the battery is not dead this morning. Going to replace the lock cylinder, as it is a bit sticky now.

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Wednesday, August 26th, 2009 AT 6:30 AM
  • Tiny
  • Raddad
  • MEMBER

All's well - replaced the alternator and redid all the battery and engine ground cables. Either the alternator was the initial problem or I messed something up while changing the diode.

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Saturday, August 29th, 2009 AT 9:55 AM
  • Tiny
  • ImpalaSS
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Hello -

Fantastic!. Thank you very much for letting us know the fix. This will definitely assist our other readers that may have a similar problem.

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Saturday, August 29th, 2009 AT 8:16 PM

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