So, about 4 years ago i was going along at 45 mph and realized i could not accelerate, and when i gave it more gas the engine started to die on me. I happened to be near a gas station so I limped in and filled up the tank ( I had 1/4 of a tank left, but i thought maybe it had gone bad or something).
About a year ago, same thing happens, 1/4 tank of gas. Make a left hand turn and it starts to die and i limp into the gas station. Fill it up and issue went away.
Well today, i left my house, filled up and about an hour after filling it up it does it again. I was making left hand turn into my neighbor hood and it flat out died and i had to coast through the intersection. I put the Jeep in neutral as i am slowly rolling and got it to start. However it had very little power, and refused to accelerate if I gave it more than the tiniest bit of gas. I had more than 3/4 of a tank of fresh gas.
I limped the 1/2 mile home and let the Jeep sit as i did some googling. I decided to go for a test drive, and the Jeep ran just fine. I could floor it and it would appropriately accelerate.
Any ideas on what i need to inspect/ replace?
Spark plugs maybe? they are due for a change, but i dont see how that would explain the gap between incidents.
I've seen posts about the crankshaft sensor, it's cheap and looks easy, so i may do that just to see if it makes a difference.

2010 JK Sahara, 2 door, automatic. 75k miles
No engine mods besides an air filter
No error codes/ Check Engine Light
Battery voltage 12.79v with the Jeep off, and 13.8v when idling.
Temperature gage looked good, more or less in the middle.
I dont recall if the dash did anything strange, i was mostly focused on getting it started and getting out of the intersection

 

I'd say the crank position sensor is a well educated guess and its easy and cheap to replace. Start there along with cleaning all grounds. Finally you need to do a load test on the battery. I had a battery that would test those exact same voltages and read good but under load it would fail. Rock auto has the CPS and its under $20. You could also pull the old one and clean it too and see if that helps in the meantime. Just wipe it off and see if its covered in crud.

 

Thanks, that gives me something to try. Less than $25 from the local parts store and looks to be an easy job for some piece of mind.
It's frustrating because the issue is intermittent and dangerous when it happens. I think i would prefer a Jeep that does not start, than a Jeep that dies seemingly randomly

 

Got a new sensor, it's going in the next day or so. Fingers crossed !

 

I'm willing to bet that is the issue. I prefer the Mopar on this sensor to rule out any issues.

 

Finally got around to do doing this. Replaced the sensor and the battery and it ran fine for my errands today. About an hour of driving.
I dunno if the battery was part of the issue, since i let the Jeep sit for some time it may have just been drained and subsequently damaged.

 

I have been dealing with the same issue. I found the ignition capacitor bolted to the back of the block behind each head. When the engine got to 210 + degrees it would trigger the sensor codes and check engine also safe mode. Ordered new capacitor but in meantime unbolted the capacitor from motor and Shazam it runs correctly, I have been dealing with this for months and have done all the suggested fixes. With replacement of sensors multiple times.
I hope this helps someone else.
I did not read this anywhere.
I am a master mechanic and marine engineer
Good luck 👍

 

Well it happened again.... stalling / surging, a complete lack of power. I am looking for suggestions
Here is what happened :

Drove to work, the Jeep seemed like it cranked longer than usual. I left work about 4 hours later, same long crank time. ( not slow to crank, just took longer to catch)
The Jeep sat for a few hours at home and i went to run an errand, same long crank. Another drive for about 30 minutes, no issues.
Started again with no issues, but soon started losing power. Could not accelerate, maintaining 20 MPH on a flat surface was difficult.
I limped it back to a gas station, the symptoms got much worse, it would completely stall, requiring me to put it in neutral and crank the engine to get it going again.
It was surging, losing power, and stalling. Luckily the last bit was down hill.
I pulled in and got about 5 gallons of gas, and waited around 20 minutes. It then drove home (~4 miles) with no issues.

Things i noticed :
Crank Position Sensor was replaced.
No warning lights, dash lights stayed on ( except when cranking to restart i think )
Battery Voltage when i got home was 12.81 volts, battery is about 8 months old.
Gas in the tank is of an unknown age... but could be a month old, or maybe a mix of older gas than that ( i dont drive the jeep often).

Stopping for 20 minutes/ topping up the gas seems like it fixed it ( but could be a coincidence )

Maybe bad gas/ gas that went bad?

The problem is hard to replicate on command, it seems to be running fine at the moment.

 

Try what Skidmore did in the post above yours?

 

I have not, since i got no error codes/ check engine light. It also did not seem like a safe mode.
It was very much a surge and stall sort of thing
Cant hurt to try however. I will look into it