engine starts.......then dies

[kbooneKJ]

i went to start my car this morning and it cranked fine and started, but then it just quit. i tried it four or five times and it just quit. finally i just gave it gas while starting it andd it stayed running but it ran like absolute crap! then i put it in drive and drove around the block and the problem went away...for now. then, after work tonight it started fine but my AVG MPG and timer on my EVIC were showing zero. my dad thinks that it is the battery which i think so also but i dont know much about electrical. a few weeks ago i went to autozone and they hooked up the computer thing to my battery and alternator and they said that everything was fine i know that autozone isnt the smartest but are they right? or is it my battery that is causing all this to happen?

 

[ThunderbirdJunkie]

may very well be the battery.

BTW, grew up in Zeeland.

 

[kbooneKJ]

oh well i guess ill go and buy a battery tomorrow then.

 

[jnaut]

Check the codes yourself. Ignition on/off/on/off/on Code will display one odometer.

 

[kbooneKJ]

i just tried the code thing and nothing showed up

 

[trail rated]

i just tried the code thing and nothing showed up

You did not turn the ignition to the "start" position, right? If you did everything right and there are no codes than the word "done" should be displayed on the odometer.

 

[sleeve]

They took that "self check" feature away after a certain model year. Probably in 2005 or 2006 - but that's just a WAG. TJKJ will know which year that feature was pulled from the KJ.

Definently the battery. The KJ runs horrible without proper voltage.

 

[kbooneKJ]

You did not turn the ignition to the "start" position, right? If you did everything right and there are no codes than the word "done" should be displayed on the odometer.
__________________

either im a dumbsh*t or mine doesnt do that. i have an 02 sport so i thought it would. i put my key in and turn it to thr front to the first click and nothing happens, the second click is when the radio and lights all come on and the third is to start the car. i go back and forth 3 times to the "on" possition and nothing displays

 

[sleeve]

Try again then... your sequence is off. It takes me a couple tries [once slow / then fast] to get it right. But I can never remember these things.

 

[kb0nly]

The first click is unlocking the steering wheel, the second click is the on/run position. Go from the on/run position back one step just so stuff shuts off, not all the way back to lock where you can remove the key, then just do that on and off and on and off, and then on and it will run the self check. Unless yours is too new.. What year is it by the way?

 

[kbooneKJ]

its an 02 sport

 

[valvestem]

I concur it sounds like the battery is going bad. The reason it came out of it a little as you drove is prolly because the alternator was pumping out enough voltage temporarily to get things going. I suggest a load test on the battery, and have the output of the alternator checked too, both very simple, quick & easy tests.

 

[kb0nly]

its an 02 sport

The 02' does have the self test, so i don't know why it wouldn't be working if you have tried that a few times. Unless its also related to your start/stop problem.

Bad PCM?? I wouldn't think so but never know. Try replacing the battery first.

 

[Powerslave]

How would a bad battery effect how it runs. If the battery was bad, it would not even crank, or start, right? It can be anything from a TPS, to MAP sensor. He also said it runs if he keeps on the gas, but horribly.

This problem happened to me once, it was an EGR valve, stuck open, you lose vacuum. IF they are stuck open at idle, and they idle rough, or just plain old stall. Any bad vacuum leak does that. It didn't throw any codes either...

I was able to remove the vacuum line that controls the valve so it closed, and it ran fine, so I LEFT it closed, and plugged the vacuum line to the EGR. Mind you, this was another vehicle, but you are explaining the same symptoms I had.

 

[Jeepin05]

Because the Liberty does a lot of weird things with a low battery, its been said on here many times. This doesn't necessarily mean it is the battery, but most of the time it is and replacing the battery is regular maintenance.

Also, by revving the motor the alternator could be feeding the power demands just enough.

But, I do agree that if the KJ can be started over and over again without hassle that the battery may be okay.

 

[Warren.fischbeck]

I'm not sure if the Lib has a serviceable feul filter or not, but that sounds like a clogged feul filter if it isn't a battery issue. The way it reads makes me think that it is a feul delivery issue when at idle or under low throttle. When you give it gas and let up on it does it stutter or die?

 

[sleeve]

Sorry for the cross linking but: Pulling Codes without a Scanner - LOST KJ's Board Here are the instructions and the time period in which the operation needs to happen. Keep trying, the 2002's will display codes in the odometer.

Also: Confirming that 8 times out of 10, replacing the Battery in the KJ will solve problems like this. Just because the battery has enough power to crank over the engine, does not mean that the suspect battery will also have enough power to supply the pcm with the 12 volts necessary to actually turn on all of the vehicle systems to actually get the KJ running.

 

[kb0nly]

How would a bad battery effect how it runs.

I know it sounds weird but its true. The battery could have enough current in it to crank but the voltage is below 12v, the PCM does weird things with low voltage on the KJ, but its not the only one. We had a similar start/stop, or crank but no start problem on the Pontiac Montana that the KJ replaced. I tried everything, MAF, TPS, FPR (fuel pressure regulator), CPS, finally i ended up replacing the battery because it wouldn't crank very fast one cold morning, and surprise problem solved... The voltage was sagging after cranking, so it would start up and then die as the full load of the electronics came online and pulled the battery down before the alternator got up to speed and kept it running. This is why i could always start it like he did, as soon as it starts i would jam the gas pedal and keep tapping it, that would keep the engine going fast enough to keep the alternator going, and i could usually drive it though it would run like crap.

 

[Powerslave]

I don't logically see it... I used a Gell Cell in my jeep, small one, it was practically DEAD, was putting out 11 volts, and no amps to start it up; so I jumped it. The JEEP Ran just fine, so how that can be true then; if I used an almost DEAD battery producing 11 volts, that would not even start the jeep, let alone RUN it; to being able to jump and run it just fine on that same WEAK battery?

IF the voltage is low like that when running, then it's a regulator, alternator, or charging voltage issue, not the battery itself unless the WAVE forms are erratic. If the low voltage logic were true, on weak OR dead battery? Well, then no liberty would run after a jump start, right? There can't be a full 12volts coming from the battery from DEAD, to JUMPing it. You get that voltage from the charging circuit. So, if it is a voltage issue causing the erratic idle, then the voltage generated is not right to the battery. If there is 13.x to 14x VDC at the battery terminals, it is going through the electrical system, any volt meter can verify that, at the battery terminals, and lighter plugs.

I am going with a sensor, or vacuum problem, or bad fuel delivery.

 

[ridenby]

Sorry for the cross linking but: Pulling Codes without a Scanner - LOST KJ's Board Here are the instructions and the time period in which the operation needs to happen. Keep trying, the 2002's will display codes in the odometer.

Also: Confirming that 8 times out of 10, replacing the Battery in the KJ will solve problems like this. Just because the battery has enough power to crank over the engine, does not mean that the suspect battery will also have enough power to supply the pcm with the 12 volts necessary to actually turn on all of the vehicle systems to actually get the KJ running.

Takes me 2-3 tries but codes come up,my libby is very touchy about battery compared to other jeep,trucks have owned.