Why won't my JK start?

Trejo

Trejo

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Joined
May 10, 2020
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6
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NORTH CAROLINA
Ok, I have an 08 3.8L 6 speed manual. No major upgrades. For two years I have been fighting a no-start issue when the outside temperature is above 65F, or so. The ONLY code it ever throws heat related is bank 2 sensor 2.
So, the problem is, I can cold start in the morning with no issues. However, after driving around for 20-30 minutes, if I turn it off, no start! All electrical works as normal, jumping off does nothing. I can push and pop all day long, but that gets pretty annoying and cannot be done everywhere. Now, yesterday, it was about 91 degrees, and I went out to start it at lunch, 3 hours after getting to work, and no start! I should mention that normally it takes 1 1/2 - 2 hours waiting for it to start back on its own, less when putting a fan blowing up on the engine. I have replaced the starter, tested out a new ignition switch, etc, etc. I am at my wit's end and really could use some help.

Any ideas? Thanks in advance, friends.
 
Battery to starter is great. Ignition to starter is 12+ volts when it's cold. After it's warmed up the Ignition side of the starter goes dead.
 
Trejo said:
Battery to starter is great. Ignition to starter is 12+ volts when it's cold. After it's warmed up the Ignition side of the starter goes dead.
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So is that with a new ign switch? But the problem could also be the neutral safety switch on the clutch pedal.
 
If it was mine i'd just put a push button starter switch on, you'll just have to remember there won't be a neutral safety switch.
 
BLACKJKU said:
If it was mine i'd just put a push button starter switch on, you'll just have to remember there won't be a neutral safety switch.
Click to expand...
Have tried doing that...
First time, starter worked great, but the security system wouldn't let it, then trying a different configuration, it was blowing the fuses...
I would to get that working...any idea which wire to attach to on the steering column? Thought we had it, but apparently not.
 
I would either pull 12v from the battery or a key on source then from the switch to the small post on the starter. Remove the Factory wire on the starter so that in case it would happen to work it doesn't cause any extra problems. Just tape the terminal up so just in case you figure out the problem you can put it back on.
 
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Definately take it to your local Oreilly, Autozone, etc. and have them check the battery for a bad cell. Had a similar issue with 2007 wouldn't start occasionally. Tested 12+V at the battery, but when under that starting load, it wouldn't supply the necessary amps.

They found a bad cell. Replaced the battery and problem never reoccurred.
 
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Another question has popped up due to some other gremlin problems.... Could this possibly be a tipm issue? I have also had random sensor issues with the fun dash lights and other exciting things that go along with it. For example, today it randomly lit up the throttle position light and shut my temp guage off...twice. Thoughts?
 
Have you cleaned the grounds? I actually added another ground strap from the battery to the alternator frame.
 
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