Quietly stalls at stop, no rough idle, no CEL

[yafacio]

So, I'm hoping you all can help me diagnose my Liberty issue. I had slow starting problem, so I replaced the battery yesterday morning. (The battery was 3 years old and in the desert that a long time.)

After, it started right up no problem. I drove 15 miles to campus, both freeway and surface streets in traffic, no problem. On the return trip, after I got off the freeway, I pulled up to a red light. When green popped up and I hit the gas... nothing. The car had quietly died. No sputter. Just dead. The only light on was the oil symbol. I put it park, started it. And got home without issue. No CEL.

Later, same day, made another 15 mile trip. After I got off the freeway, I went a few miles. Hit a red light (not the first one, maybe the 3rd) car quietly dies. Same thing. Green light, I hit the gas... nothing. I restart and get to my destination no problem. Again, the only thing I see while the car is dead is oil symbol.

During both these drives I have the A/C running. And after the battery replacement when I had the car running with the hood up I noticed that the A/C compressor was making a little noise when the pulley engaged. The A/C compressor is only 5 years old.

Could the belt be slipping and cause the car to quietly die?

When the car is running, no problems, no lights, no rough idle.

Info: Liberty 2006, gas, 120k (30 of those towed behind RV) mechanically awesome, dry no leaks. It's, well, perfect and the love of my life.

HELP!

 

[LibertyTC]

When I replace a battery, I use emery cloth or wire brush/rough up the interior of lugs, to ensure they make a good clean contact before install.
Also ensure they are on there tight. Sealed AGM (absorb glass mat) batteries are preferred as thy wont offer any terminal corrosion.
Also the IAC controls the idle and the port can get really bad with carbon, try cleaning...
See post #10 : https://www.jeepkj.com/threads/idle-air-control-no-screws.44826/

 

[yafacio]

When I replace a battery, I use emery cloth or wire brush/rough up the interior of lugs, to ensure they make a good clean contact before install.
Also ensure they are on there tight. Sealed AGM (absorb glass mat) batteries are preferred as thy wont offer any terminal corrosion.
Also the IAC controls the idle and the port can get really bad with carbon, try cleaning...
See post #10 : https://www.jeepkj.com/threads/idle-air-control-no-screws.44826/

Thanks! Yes, all cleaned up, newer post cables, no corrosion, nice and tight. I purchased an Interstate which is what I've used in the past.

I'll check idle air control as suggested.

What is weird is the problem presented AFTER the battery change, same day. So odd.

 

[lfhoward]

Yes, I was going to suggest cleaning the IAC too. Been there, done that, in my 2000 XJ. Same exact symptoms. Use Throttle Body cleaner (not Carb cleaner) and an old toothbrush.

 

[yafacio]

Does it make sense to just replace it? I mean they aren't super expensive....

 

[LibertyTC]

Yes sure you can replace it, & the Jeep prefers Mopar parts= #4861552AC.
Clean the interior port though, it is going to be dirty.

 

[yafacio]

Okay, I cleaned the IAC based on all your information. I decided to clean it first to make sure it was, in fact, the problem.

Let me just say... magic. Like EVERYone should clean their IAC. It wasn't super dirty like expected but my Jeep ran smoother instantly. It drove like a new vehicle and it ran pretty damn good to begin with. No red light death occurred. I'm hoping the dirty IAC was the problem.

I do not see a need to replace it. The o-rings looked good, the plastic components looked good, the spring felt good.

McLibby is one happy girl! Me too! THANK YOU ALL SO MUCH!

 

[lfhoward]

So glad to hear it worked!! Enjoy the free fix!