LOST JEEPS :: View topic - 2009 Liberty random hot start problem.

Back again (after 4 years lol)

Still have the Liberty.
Still have the problem.

Again, this happens most often when we try to restart within a few minutes of shutting down.
The example above of "running into a store for a snack" is a good one.

The jeep will crank and start instantly as always, but the starter stays engaged. The engine is running but at a very low rpm and with considerable shaking. It will not recover from this, if the key is kept on it will do this forever.

Shutting off and retrying is most always unsuccessful, even repeatedly.

Retrying with the throttle pedal have way down always works, she's roar to life and all is well.

When I did plugs and things 3-4 years ago, that helped a lot. It was probably a year before it happened again. But as time goes by, it's happening more and more often. A couple times a month now. It is a worry. My wife's car, and she often goes into Great Smoky Mountains National Park to take pictures. Stopping and restarting, moving here and there, often. Yesterday it happened to her on the way to the Park, and she had to call me, she couldn't remember the trick and couldn't get her car to start.

Thank God it happened where she had a signal, she was able to call me, and I was able to help her get it going.

There is no cellular service in Great Smoky Mountains National Park!

I spent yesterday afternoon at Rocky Top Jeep test driving new wranglers.
She still doesn't want to spend the money. That damned Liberty (10 years old now, 153,000 miles, plus 60k dragged behind the motorhome) is still the best car she's ever had.

I got to fix this for good, for my own peace of mind at this point.
I'll do plugs and filters tomorrow, maybe coil packs too. Also gonna get a gas cap, the only code that car has ever thrown is an evap leak.

What about this cam sensor?
Where is it?
It is easy to get to and change?
But would that set a code? (we never get a code)

The problem "feels" to me like the PCM simply doesn't believe the engine is running. It's still trying to start it.
How does the PCM know if it's running?

jimragtop wrote:

Back again (after 4 years lol)
Still have the Liberty.
Still have the problem.
Again, this happens most often when we try to restart within a few minutes of shutting down.
The example above of "running into a store for a snack" is a good one.
The jeep will crank and start instantly as always, but the starter stays engaged. The engine is running but at a very low rpm and with considerable shaking. It will not recover from this, if the key is kept on it will do this forever.
Shutting off and retrying is most always unsuccessful, even repeatedly.
Retrying with the throttle pedal have way down always works, she's roar to life and all is well.
When I did plugs and things 3-4 years ago, that helped a lot. It was probably a year before it happened again. But as time goes by, it's happening more and more often. A couple times a month now. It is a worry. My wife's car, and she often goes into Great Smoky Mountains National Park to take pictures. Stopping and restarting, moving here and there, often. Yesterday it happened to her on the way to the Park, and she had to call me, she couldn't remember the trick and couldn't get her car to start.
Thank God it happened where she had a signal, she was able to call me, and I was able to help her get it going.
There is no cellular service in Great Smoky Mountains National Park!
I spent yesterday afternoon at Rocky Top Jeep test driving new wranglers.
She still doesn't want to spend the money. That damned Liberty (10 years old now, 153,000 miles, plus 60k dragged behind the motorhome) is still the best car she's ever had.
I got to fix this for good, for my own peace of mind at this point.
I'll do plugs and filters tomorrow, maybe coil packs too. Also gonna get a gas cap, the only code that car has ever thrown is an evap leak.
What about this cam sensor?
Where is it?
It is easy to get to and change?
But would that set a code? (we never get a code)
The problem "feels" to me like the PCM simply doesn't believe the engine is running. It's still trying to start it.
How does the PCM know if it's running? >>> (Answer) It knows from the pulse signal received from the crank speed sensor.

I've been struggling with this same issue on my 09 KK for about 4 years now and have been reading threads with no real solutions given.
What I've found:
- Never happens when the trucks cold
- hot weather, hot engine ..
- 5 minute stop to fill the tank and turn her on .. all's good
- 60 minute stop (grocery shopping) .. all's good
- .. somewhere in the 10-20 minute area .. getting sandwiches from a shop kind of time range .. she does the no start
When she doesn't start, I do the key off/on thing to prime the fuel line (no change), let her crank until she stops & on the 3rd attempt she'll start
I found this doesn't happen during the short stops if I open the hood while stopped OR (this is how I figured it out for myself) purge a little bit of gas from the fuel rail from the schrader valve. If I purge the rail, she starts up immediately .. obviously not a good idea over a hot engine & I hate smelling like gas afterwards, but it "fixes" it for that time.
I've had the truck for 8 years and this is the only real issue I've had with her at 150k miles and she's only been doing it for the last 3/4 years. I really don't want to start throwing parts at her but it definitely seems to be heat soak for me and I'm unsure what changed to make this an issue as she ages.

Thanks for the reply - I thought the heat soaking people talked about was general engine compartment heat soaking in and causing the fuel to vaporize in the line. Did I misunderstand?

If it's a fuel heat related vapor lock issue, insulate your fuel lines and fuel rail on top of the engine.
The insulated and reflective heat shield tubing over the fuel lines and fuel rails will solve any heat related vapor lock issues.

...(this is how I figured it out for myself) purge a little bit of gas from the fuel rail from the schrader valve. If I purge the rail, she starts up immediately .. obviously not a good idea over a hot engine & I hate smelling like gas afterwards, but it "fixes" it for that time.

Retrying with the throttle pedal have way down always works, she's roar to life and all is well.

When this happens to mine, I turn it off, then to RUN for 5 seconds to prime the fuel pump and get pressure back in the line. After that it always starts.

I plan on changing out my tired old fuel pump soon. I think it lets fuel seep backward into the tank allowing for “vapor lock” in the fuel rail after shutoff when the engine is hot. Hope the new fuel pump solves it permanently.

Author:	jimragtop [ Sun Mar 15, 2020 1:18 pm ]
Post subject:	Re: 2009 Liberty random hot start problem.
Back again (after 4 years lol) Still have the Liberty. Still have the problem. Again, this happens most often when we try to restart within a few minutes of shutting down. The example above of "running into a store for a snack" is a good one. The jeep will crank and start instantly as always, but the starter stays engaged. The engine is running but at a very low rpm and with considerable shaking. It will not recover from this, if the key is kept on it will do this forever. Shutting off and retrying is most always unsuccessful, even repeatedly. Retrying with the throttle pedal have way down always works, she's roar to life and all is well. When I did plugs and things 3-4 years ago, that helped a lot. It was probably a year before it happened again. But as time goes by, it's happening more and more often. A couple times a month now. It is a worry. My wife's car, and she often goes into Great Smoky Mountains National Park to take pictures. Stopping and restarting, moving here and there, often. Yesterday it happened to her on the way to the Park, and she had to call me, she couldn't remember the trick and couldn't get her car to start. Thank God it happened where she had a signal, she was able to call me, and I was able to help her get it going. There is no cellular service in Great Smoky Mountains National Park! I spent yesterday afternoon at Rocky Top Jeep test driving new wranglers. She still doesn't want to spend the money. That damned Liberty (10 years old now, 153,000 miles, plus 60k dragged behind the motorhome) is still the best car she's ever had. I got to fix this for good, for my own peace of mind at this point. I'll do plugs and filters tomorrow, maybe coil packs too. Also gonna get a gas cap, the only code that car has ever thrown is an evap leak. What about this cam sensor? Where is it? It is easy to get to and change? But would that set a code? (we never get a code) The problem "feels" to me like the PCM simply doesn't believe the engine is running. It's still trying to start it. How does the PCM know if it's running?

Author:	teller34 [ Wed Mar 18, 2020 8:54 am ]
Post subject:	Re: 2009 Liberty random hot start problem.
When it does it; does it have a heavy smell of gas or anything like that. I had Chevy pickup and it had starting issues. We replaced everything. It finally wouldn’t start. We took it to the shop and it wound up being a $20 temp sensor telling the computer it was 20 bellow 0 and was chocking the motor out. Sent from my iPhone using Tapatalk

Author:	juniorx [ Mon Jun 01, 2020 12:06 pm ]
Post subject:	Re: 2009 Liberty random hot start problem.
jimragtop wrote: Back again (after 4 years lol) Still have the Liberty. Still have the problem. Again, this happens most often when we try to restart within a few minutes of shutting down. The example above of "running into a store for a snack" is a good one. The jeep will crank and start instantly as always, but the starter stays engaged. The engine is running but at a very low rpm and with considerable shaking. It will not recover from this, if the key is kept on it will do this forever. Shutting off and retrying is most always unsuccessful, even repeatedly. Retrying with the throttle pedal have way down always works, she's roar to life and all is well. When I did plugs and things 3-4 years ago, that helped a lot. It was probably a year before it happened again. But as time goes by, it's happening more and more often. A couple times a month now. It is a worry. My wife's car, and she often goes into Great Smoky Mountains National Park to take pictures. Stopping and restarting, moving here and there, often. Yesterday it happened to her on the way to the Park, and she had to call me, she couldn't remember the trick and couldn't get her car to start. Thank God it happened where she had a signal, she was able to call me, and I was able to help her get it going. There is no cellular service in Great Smoky Mountains National Park! I spent yesterday afternoon at Rocky Top Jeep test driving new wranglers. She still doesn't want to spend the money. That damned Liberty (10 years old now, 153,000 miles, plus 60k dragged behind the motorhome) is still the best car she's ever had. I got to fix this for good, for my own peace of mind at this point. I'll do plugs and filters tomorrow, maybe coil packs too. Also gonna get a gas cap, the only code that car has ever thrown is an evap leak. What about this cam sensor? Where is it? It is easy to get to and change? But would that set a code? (we never get a code) The problem "feels" to me like the PCM simply doesn't believe the engine is running. It's still trying to start it. How does the PCM know if it's running? I've been struggling with this same issue on my 09 KK for about 4 years now and have been reading threads with no real solutions given. What I've found: - Never happens when the trucks cold - hot weather, hot engine .. - 5 minute stop to fill the tank and turn her on .. all's good - 60 minute stop (grocery shopping) .. all's good - .. somewhere in the 10-20 minute area .. getting sandwiches from a shop kind of time range .. she does the no start When she doesn't start, I do the key off/on thing to prime the fuel line (no change), let her crank until she stops & on the 3rd attempt she'll start I found this doesn't happen during the short stops if I open the hood while stopped OR (this is how I figured it out for myself) purge a little bit of gas from the fuel rail from the schrader valve. If I purge the rail, she starts up immediately .. obviously not a good idea over a hot engine & I hate smelling like gas afterwards, but it "fixes" it for that time. I've had the truck for 8 years and this is the only real issue I've had with her at 150k miles and she's only been doing it for the last 3/4 years. I really don't want to start throwing parts at her but it definitely seems to be heat soak for me and I'm unsure what changed to make this an issue as she ages.

Author:	WWDiesel [ Mon Jun 01, 2020 12:29 pm ]
Post subject:	Re: 2009 Liberty random hot start problem.
juniorx wrote: jimragtop wrote: Back again (after 4 years lol) Still have the Liberty. Still have the problem. Again, this happens most often when we try to restart within a few minutes of shutting down. The example above of "running into a store for a snack" is a good one. The jeep will crank and start instantly as always, but the starter stays engaged. The engine is running but at a very low rpm and with considerable shaking. It will not recover from this, if the key is kept on it will do this forever. Shutting off and retrying is most always unsuccessful, even repeatedly. Retrying with the throttle pedal have way down always works, she's roar to life and all is well. When I did plugs and things 3-4 years ago, that helped a lot. It was probably a year before it happened again. But as time goes by, it's happening more and more often. A couple times a month now. It is a worry. My wife's car, and she often goes into Great Smoky Mountains National Park to take pictures. Stopping and restarting, moving here and there, often. Yesterday it happened to her on the way to the Park, and she had to call me, she couldn't remember the trick and couldn't get her car to start. Thank God it happened where she had a signal, she was able to call me, and I was able to help her get it going. There is no cellular service in Great Smoky Mountains National Park! I spent yesterday afternoon at Rocky Top Jeep test driving new wranglers. She still doesn't want to spend the money. That damned Liberty (10 years old now, 153,000 miles, plus 60k dragged behind the motorhome) is still the best car she's ever had. I got to fix this for good, for my own peace of mind at this point. I'll do plugs and filters tomorrow, maybe coil packs too. Also gonna get a gas cap, the only code that car has ever thrown is an evap leak. What about this cam sensor? Where is it? It is easy to get to and change? But would that set a code? (we never get a code) The problem "feels" to me like the PCM simply doesn't believe the engine is running. It's still trying to start it. How does the PCM know if it's running? >>> (Answer) It knows from the pulse signal received from the crank speed sensor. I've been struggling with this same issue on my 09 KK for about 4 years now and have been reading threads with no real solutions given. What I've found: - Never happens when the trucks cold - hot weather, hot engine .. - 5 minute stop to fill the tank and turn her on .. all's good - 60 minute stop (grocery shopping) .. all's good - .. somewhere in the 10-20 minute area .. getting sandwiches from a shop kind of time range .. she does the no start When she doesn't start, I do the key off/on thing to prime the fuel line (no change), let her crank until she stops & on the 3rd attempt she'll start I found this doesn't happen during the short stops if I open the hood while stopped OR (this is how I figured it out for myself) purge a little bit of gas from the fuel rail from the schrader valve. If I purge the rail, she starts up immediately .. obviously not a good idea over a hot engine & I hate smelling like gas afterwards, but it "fixes" it for that time. I've had the truck for 8 years and this is the only real issue I've had with her at 150k miles and she's only been doing it for the last 3/4 years. I really don't want to start throwing parts at her but it definitely seems to be heat soak for me and I'm unsure what changed to make this an issue as she ages. If it's a fuel heat related vapor lock issue, insulate your fuel lines and fuel rail on top of the engine. The insulated and reflective heat shield tubing over the fuel lines and fuel rails will solve any heat related vapor lock issues. Heat Shield Sleeve and Looms:> https://www.heatshieldproducts.com/auto ... d-sleeving https://www.heatshieldproducts.com/blog ... vapor-lock

Author:	teller34 [ Mon Jun 01, 2020 2:34 pm ]
Post subject:	Re: 2009 Liberty random hot start problem.
On an old truck of mine. I had pcv valve cause the truck to stall and then not start when it was hot. That was a long time ago though. Sent from my iPhone using Tapatalk

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Author:	mushupork [ Sat Dec 18, 2021 5:28 pm ]
Post subject:	Re: 2009 Liberty random hot start problem.
After a lot of online searching today, YouTube and forums, I find myself back at LostJeeps and a post that describes exactly what happened to me In Nov 2017 we bought this 2012 KK Limited as a Jeep Certified used vehicle from a dealer. On Wed I drove 30 mins from home. Stopped and got out, ran an errand for maybe 15/20 mins and got back in and the KK would not start. This has never happened before I tried a couple more starts which did not work - the vibrating and dash lighting up like this video I found online ... https://www.youtube.com/watch?v=FVTF0vcndM4 I sat in the drivers seat and I googled from my phone to remember how to do the key flip to show error codes on the odometer like I have with previous Jeep vehicles but there was no code. The time it took to do the searching and key flipping I guess was enough to let things settle/cool down and I was able to start the car and it ran like nothing ever was wrong. I did make a couple other short stops too on the way home and this did not happen again. The talk about "heat soak" is really interesting because I just had the heater core flushed a month ago and it is hotter than it has ever been. I was getting only lukewarm heat in November in the cabin before but after the service it gets very warm. I wonder if that is coincidence or related? What exactly do others do to work around this since there is no "fix"? 1) To get it started - I think someone said try to restart the car again after the first failed start with the gas pedal half down but I had pumped the gas a couple times while I was trying to get it started and it had no effect for me. 2) To prevent the situation - Has anyone used the thermal barriers mentioned and if so did it work? Where exactly did you apply it and how much? I know this is an old thread but it is exactly what I experienced too. Thanks for any help.

Author:	WWDiesel [ Sat Dec 18, 2021 9:41 pm ]
Post subject:	Re: 2009 Liberty random hot start problem.
So exactly what part is heat sinking? PCM or one of the engine sensors? You really need to narrow it down if possible. The shotgun approach does not always work out well. Once you determine what is the main cause of the hot start failure, i.e. it should be relatively simple to address that specific culprit part.

Author:	mushupork [ Sat Dec 18, 2021 11:23 pm ]
Post subject:	Re: 2009 Liberty random hot start problem.
Thanks for the reply - I thought the heat soaking people talked about was general engine compartment heat soaking in and causing the fuel to vaporize in the line. Did I misunderstand?

Author:	WWDiesel [ Sun Dec 19, 2021 12:01 am ]
Post subject:	Re: 2009 Liberty random hot start problem.
mushupork wrote: Thanks for the reply - I thought the heat soaking people talked about was general engine compartment heat soaking in and causing the fuel to vaporize in the line. Did I misunderstand? The fuel system is under pressure from the fuel pump inside the fuel tank, so old fashion "vapor lock" should not be a possibility on a modern fuel injected vehicle. But a sensor getting hot and failing to function properly is a possibility.

Author:	mushupork [ Sun Dec 19, 2021 2:49 pm ]
Post subject:	Re: 2009 Liberty random hot start problem.
Thanks again WWDiesel. I have re-read this thread a couple times more and I just noticed it was you who suggested in June 2020 to insulate the fuel lines and rail. Did anyone try the insulation and the forum decided it didn't help after all? WWDiesel: Quote: If it's a fuel heat related vapor lock issue, insulate your fuel lines and fuel rail on top of the engine. The insulated and reflective heat shield tubing over the fuel lines and fuel rails will solve any heat related vapor lock issues. I also see juniorx's note about the schrader valve on the fuel rail and found a YouTube video that demonstrates about purging. I am not a mechanic but this is basically a pressure valve isn't it? Releasing the pressure manually this way then allows fuel to flow and the KK to start. There is a difference between this and true vapor lock (fuel injected vehicles can't be vapor locked) but the symptom seems the same. juniorx said: Quote: ...(this is how I figured it out for myself) purge a little bit of gas from the fuel rail from the schrader valve. If I purge the rail, she starts up immediately .. obviously not a good idea over a hot engine & I hate smelling like gas afterwards, but it "fixes" it for that time. I also found this YouTube video demonstrating what juniorx above described. Releasing fuel from the schrader valve allows the KK to be started : https://www.youtube.com/watch?v=JTH-TASBH0Q Does anyone have experience tapping or holding down the gas pedal help in getting it to start like jimragtop said? Since this has happened just once but I share this vehicle with my wife, I am most interested in what to do when stuck if she calls me. jimragtop said: Quote: Retrying with the throttle pedal have way down always works, she's roar to life and all is well. Thanks again - I am trying to organize this info as best I can. Hopefully it is not too hard to follow.

Author:	lfhoward [ Wed Dec 29, 2021 11:36 pm ]
Post subject:	Re: 2009 Liberty random hot start problem.
When this happens to mine, I turn it off, then to RUN for 5 seconds to prime the fuel pump and get pressure back in the line. After that it always starts. I plan on changing out my tired old fuel pump soon. I think it lets fuel seep backward into the tank allowing for “vapor lock” in the fuel rail after shutoff when the engine is hot. Hope the new fuel pump solves it permanently.

Author:	ClydeGarden [ Thu Jan 20, 2022 11:13 pm ]
Post subject:	Re: 2009 Liberty random hot start problem.
Last month I had the same problem with my car. My friend told me to wait a few minutes before driving the car. It's like letting the car rest. I tried it and it worked

Author:	JeepMonkey190 [ Tue Jan 17, 2023 8:35 pm ]
Post subject:	Re: 2009 Liberty random hot start problem.
lfhoward wrote: When this happens to mine, I turn it off, then to RUN for 5 seconds to prime the fuel pump and get pressure back in the line. After that it always starts. I plan on changing out my tired old fuel pump soon. I think it lets fuel seep backward into the tank allowing for “vapor lock” in the fuel rail after shutoff when the engine is hot. Hope the new fuel pump solves it permanently. I am now also having this problem with my 2011 kk (180k miles) did the new fuel pump solve the problem?

Author:	JeepMonkey190 [ Wed Jan 18, 2023 12:25 pm ]
Post subject:	Re: 2009 Liberty random hot start problem.
I can’t afford to buy another vehicle right now and it’s my only vehicle for the whole family has any figured out anything more on this problem??? Edit: talked to a mechanic over the phone and told him all our story and he is to believe that it it not the pump since it does start wether rough or not, he thinks it sounds more like a bad injector but he won’t tell me fully until I pay for a diagnostic.

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Author:	KKboy [ Sun Mar 17, 2024 9:05 am ]
Post subject:	Re: 2009 Liberty random hot start problem.
I’ve been experiencing the same starting problem with my 2008 for a couple of years. No codes at any time. A mechanic just checked fuel pump which was replaced 5 years ago and reported the pressure valve was holding within specs when the pump was off. I learned to use the shut off -turn to Run - wait 4 secs - start sequence and that worked reliably until a year ago. Now it takes at least two of these to start when hot sputtering happens. As this only happens when engine is hot and no codes are recorded, it seems to be temperature related. I’m about to install Thermotec insulation- a difficult job to do effectively because the rail mounting brackets require cutouts as well as the injectors. I will try to create a template first, then transfer the pattern to the insulation. Will report back on outcome. If others have done this please share.

Author:	WWDiesel [ Sun Mar 17, 2024 11:54 am ]
Post subject:	Re: 2009 Liberty random hot start problem.
Based on your description of the issue, I would say you have a leaking injector(s). Need a mechanic with a good high end scanner to run an injector leak down test.