Libby starts and then dies.

eliotal said:

I am starting to think that the sentry key might be the problem.

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But you said it stays running if you give it gas...

if you have another vehicle, try swapping the batterys

my jeep (before I replaced my battery) would stall inless I floored the gas, but i didn't try and drive it like that, of course after stalling it 2x it wouldn't start up anyway, my battery was 3 years old, I just went and got another one, problem sovled

i know you said yours was only 1 year old, still have a warrenty on it?
might be worth looking at

Nooby said:

if you have another vehicle, try swapping the batterys

my jeep (before I replaced my battery) would stall inless I floored the gas, but i didn't try and drive it like that, of course after stalling it 2x it wouldn't start up anyway, my battery was 3 years old, I just went and got another one, problem sovled

i know you said yours was only 1 year old, still have a warrenty on it?
might be worth looking at

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Ding,Ding I think we have a winner!! KJ's like GOOD batteries. Weirdest acting sob ever saw about batteries.

I'll have the battery looked at. I tested it and it had 12.7 volts but it later went down to 12.4. I don't know much about testing batteries, so over the weekend I will have it tested.

It is the battery. I had exact same thing about a year ago. I had to pump gas while at red lights lol. Swapped out batt and no more problems.

eliotal said:

I'll have the battery looked at. I tested it and it had 12.7 volts but it later went down to 12.4. I don't know much about testing batteries, so over the weekend I will have it tested.

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Xodius said:

It is the battery. I had exact same thing about a year ago. I had to pump gas while at red lights lol. Swapped out batt and no more problems.

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Been there,done that. If the batt. is over 2 years old it is on its last leg for the KJ. Amazing how picky Libby is about this stuff.

I may be wrong, but I probably have one of the oldest batteries in a KJ. I'm not the original owner, but the battery under my hood says "Chrysler Corporation...Maintance-Free Battery" It doesn't appear to have a code date but I don't think the previous owner would have went to the Jeep dealer for a battery as they were an ACDELCO distributor. My KJ is a 2003.

auburn4193 said:

I may be wrong, but I probably have one of the oldest batteries in a KJ. I'm not the original owner, but the battery under my hood says "Chrysler Corporation...Maintance-Free Battery" It doesn't appear to have a code date but I don't think the previous owner would have went to the Jeep dealer for a battery as they were an ACDELCO distributor. My KJ is a 2003.

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Amazing,I guess 1 out of a thousand or even ten thousand.

I think it depends on the environment too. I am in the desert and the stock battery lasted...4 years. Then I was on a battery a year kick for a long time. My current batt is a optima yellow top...we will see if it makes it past a year. I installed it on 10/10/10 lol. So far so good but it is still new. I will keep you posted if it craps out or when it does.

auburn4193 said:

I may be wrong, but I probably have one of the oldest batteries in a KJ. I'm not the original owner, but the battery under my hood says "Chrysler Corporation...Maintance-Free Battery" It doesn't appear to have a code date but I don't think the previous owner would have went to the Jeep dealer for a battery as they were an ACDELCO distributor. My KJ is a 2003.

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My OEM battery was pretty old when it went about 1-1/2 years ago. My KJ is an '02 (build date was 9/2001). I will tell you this... it went without warning. No funky tailgate clicking, or flickering lights, or trouble staying running. It got me to the store and back like it always did, and the next trip it was dead. I couldn't even jump start it off another vehicle.

So, be careful if you have a long trip away from home planned.

I ran my OEM battery over 100k miles on my 05. Just changed it out a couple months ago. At oil changes, I would read the voltage and check the cells with a hydrometer. Voltage was 12ish, engine off, but a couple cells were slow to have all four balls float. About 90k miles I started seeing the CEL for cylinder 3 misfire. It would go off after a few days. Then I started getting the CEL for cylinder 3 misfire & multiple cylinder misfire. I noticed this would happen after idling for extended periods. (10+ minutes) and worse if the headlights and heater were on. Finally, coming home one night, had the lights, defrost, fog lights, wipers, stereo all on and stopped to check the mail. I left the Jeep idling and when the a/c caused the cooling fan to kick on, the engine nearly stalled, the headlights went dim and the RPM's dropped to 300 before it recovered. On advice from this site, I replaced the battery and I have not had a single CEL or other issue. Ole girl runs great!

It is good to check your battery with hydrometer and voltages.
Once a year in the fall (before winter) is a good time to have a load test performed.
I charge my batteries with an intelligent manual charger once a month.
http://www.jeepkj.com/forum/showthread.php?t=47021

changed ckp sensor and battery now car is running good. Damn battery, luckily they swapped it for free. thanx for everything guys