Shuts off by itself, quits running

[Ghost00TJ]

Starts and doesn't stay running, sometimes it runs fine and stays running. So yes an intermittent problem (those are the most fun). Volt guage shows 14v but hand held meter shows 12.67v while running.

So I had the Alt and Battery tested, both are good. Took apart all connectors whipped off and gooed with dielectric grease. Started just fine -stronger than before-and seems ok. We'll see what happens later.

Any suggestions?

[brian613]

it sounds to me like your fuel pump could be going out.
my truck did something similar when the fuel pump started going out it would run great some times then for no reason it would shut off and not start for days..

[Ghost00TJ]

this would act like it was a low battery and turn over slow.

[crazy4ink]

Check your crank position sensor and cam position sensor

[hobbyshopass]

You already fixed the wire connection. After fixing the connection what was voltage at battery while running. Did it match gauge.

Even with the battery cable off it should run of Alternator. Have you checked you Distributor cap and rotor, also if the distributor gear is worn it can throw the timing off making it turn over hard. I am trying to cover all basis. If there is any other factors I can help more.

[Ghost00TJ]

I forgot while cleaning and greasing connections I removed the Jet Chip and it was kinda falling apart, so I left it out greased the brain box connectors also. The last couple days have shown no problems and in fact noticeably faster and stronger starts.
Maybe normal PM was the key, who'd athunk it?

The chip I bought used and have ran it for almost 2 years now. JC stage 1

[hobbyshopass]

The most common prob on vehicles is loose connection at the battery.
glad thats all you had wrong

[Jerry Bransford]

Even with the battery cable off it should run of Alternator.

No, it won't. Modern Jeep alternators won't work unless they receive a required 12 volt "exciter" voltage from the battery. Without the battery, the alternator won't put anything out and thus the engine won't run. Some other alternators and all generators will work without the battery but not the TJ's alternator.

You can't even push-start a TJ with a completely dead battery for the same reason. If the battery is not completely dead but just doesn't have the power to turn the starter motor, you can push-start it and the engine will start since an only partially-dead battery can still put out enough power for a light load like the alternator presents. But if the battery is totally dead, it's not gonna work.

My first thought is perhaps the crankshaft position sensor is going bad. Mounted next to the flywheel where it generates the engine's master timing signal, the engine will die anytime the CPS hiccups or dies. They usually go intermittent first before totally dying

[Ghost00TJ]

Well it did it again today, No codes. Just acts as if there is not enough juice to turn over, luckily it started and seemed to run fine once I revved it up a second or 2.

I havent had the starter checked yet?

And on newer vehicles you can cause damage by disconecting the battery while it's running, cant remeber the specifics but this I read a couple years ago.

[Jerry Bransford]

I think I may have misunderstood your problem. So it's not dying while you drive it? It just has trouble staying running once started and it has trouble even turning over with the starter motor? Have you done a load test on the battery yet? I take it both battery connections have been cleaned and tightened?