TJ dies, then wouldn't start, then wouldn't idle, now runs fine.

[K1dS3ns4t10n]

I'm hoping someone here can help me with a strange problem with my 2001 TJ. Its got a 4.0L and a 5-speed and just under 70,000 miles.

I was on my way to work Monday, and while I was driving the engine just quit. I was in 2nd or 3rd gear and wasn't shifting at the time it died. I pulled over and it wouldn't start just cranked. Dash lights worked, radio worked, head lights worked, etc. After a couple minutes it finally started but then would not idle. I could keep it running by giving it gas if I kept the RPM's at about 2000 or higher, but as soon as I let off the gas and the RPM's dropped it would quit. After about 10 minutes it finally was able to hold idle, but the check engine light was on. From there I drove it about 5 miles to a friend of mine who is a mechanic and it died two more times on the way there, but this time fired right up and idled each time.

There were four codes stored in the computer but I don't know the exact numbers. The codes were cam sensor, oxygen sensor, and two auto shutdown codes. After leaving my jeep at my friends shop overnight, he reset the codes and they did not come back even after driving it for about 20 miles and letting it idle at the shop for a while.

So basically he didn't find anything wrong, and its running fine now. I'm worried that its going to quit on me again when I least expect it. Anyone here have any suggestions?

[juanez]

I had a very simialr experience about 6 months ago. TJ was driving normally. I stop at the post office and run inside for maybe 2 minutes. When I came out and tried to start the engine it would turn over and finally start, but die as soon the RPMs went below 2000 or so. No was it was driveable.

I poked around under the hood for a few minutes, then tried to start it up again....it started totally normally and has run fine ever since.

Wierd.

[Mattholomew]

During the rolling death the computer may have reset itself, possibly giving you the choppy idle once you got it to turn-over.


my 2¢

[BNovak]

Has it stuttered at all when driving?

Either post the codes it was throwing (I have a FSM I can check for you) or go to auaotzone and have them tell you what's broken...

If so it might be a throttle position sensor failing. Could also be the crankshaft position sensor. If it's throwing codes it's definently a sensor though so that's a good thing!

[rockguy]

You could always check the fuel filter, Back to basics you know

[Fox Fader]

Originally Posted by rockguy

You could always check the fuel filter, Back to basics you know

Do you know where the fuel filter is?

[rockguy]

Regardless of where it is the symptoms he described could very well be a clogged fuel filter

[HowUDerin]

dead battery maybe? mine died a while back and the jeep would only run above 2000rpm......just a thought

[superubicon]

Sounds to me like your gas cap wasnt/isnt on tight enough. I've seen it a few times with the symtoms you describe. Make sure you hear the clicks when putting you cap back on.

[K1dS3ns4t10n]

Its never stuttered when driving prior to it quitting. I'll have to see if my friend remembers or wrote down the actual code numbers that were thrown. He put the cam sensor on a scope and said the voltage was fine.

I've heard of a loose gas cap setting a check engine light but I've never heard one causing the vehicle to die, not start or not idle. Stranger things have happened I suppose.

[superubicon]

Originally Posted by K1dS3ns4t10n

Its never stuttered when driving prior to it quitting. I'll have to see if my friend remembers or wrote down the actual code numbers that were thrown. He put the cam sensor on a scope and said the voltage was fine.

I've heard of a loose gas cap setting a check engine light but I've never heard one causing the vehicle to die, not start or not idle. Stranger things have happened I suppose.

A loose cap will indeed make a tj spit,sputter and die. It has something to do with pressure in the tank. Strange but true.

[Ozzy817284]

sounds like your cam sensor is on its way out. The cam sensor will cause it to die, and if it gets a partial signal will cause it to run like poop. i would replace it.

[blueknight44]

Fuel filters are in the gas tank on a 99TJ, IAC valves: idle air control valve, located on the throttle body can carbon up, I have a idle slow speed issue.

[TheFredElement]

I had a bad gas cap on my old 99 cherokee, it threw a check engine with a specific "bad gas cap code"

[K1dS3ns4t10n]

ok well thanks for all the input guys but I found the problem.. the hard way.

I was at the quarter car wash with the engine running and all of a sudden the horn started blaring so I popped the hood and disconnected the horns. I thought that was odd but figured something must have gotten wet, and went about washing the car. Then the motor stalled.. hmm oh well no time to mess with that because time is running out on the car wash timer. Then the next thing I know the starter is cranking and the engine starts on its own. The keys were still in the ignition from when it stalled but I wasnt near them and I don't have a remote start. After the motor started the starter just kept cranking and of course its grinding away. I gave up on the car wash and jumped inside to shut her down, but when I take the keys out nothing happens... the motor is still running and the starter is still cranking. I stalled the motor by holding my foot on the brakes and putting it in gear.

At this point the engine is stopped but the starter is still cranking and by this time I'm sure the starter is toast. I pop the hood again and pulled the starter relay which finally made the starter quit. Then I notice sparks shootin out from underneath the relay box where the starter relay was so I pull all the relays in there and desparately search my jeep for some tools to disconnect the battery.

No luck on the tool search.. and there was nobody else around at the car wash so I call my dad whos not too far away and told him to bring me some tools and (fearing the worst) a fire extinguisher. He thought I was joking so after convincing him that I wasn't he was on his way.. At about that time someone else finally pulls into the car wash and I ask him if he has any tools but all he could offer me was a bottle opener. Horrid images of Macguyver flash through my head, but I told him thanks but no thanks on the bottle opener. After 10-15 minutes of me watching sparks fly my dad finally shows up with some tools and I was able to disconnect my battery.

I had it towed back to my friends shop and what had happened was the wires in the wire harness feeding into the relay box that sits over the front passenger wheel had worn through the tape down to bare metal and were all melted together. In that box along with the starter relay, there is a horn relay, ASD relay and O2 sensor relay. This explains the ASD and O2 sensor codes I had the week before. One rebuilt starter and some delicate surgery on the wire harness and I was back on the road.

Luckily nothing else seems to have been fried in the ordeal. It could have been much worse. I'm lucky it wasn't in gear when the starter was continously cranking, or I probably would have had to chase it down.