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-   -   Zj died, won't start. (http://www.jeepforum.com/forum/f13/zj-died-wont-start-1600113/)

AnotherRedZj 09-18-2013 05:36 PM

While I was out wheeling a bit today it Jus shut down on me. Got it towed home and started messing with it. Seems its not getting spark.

I've been reading the "12 things....." Thread but am very a.d.d so I think alot got by me. First step seems to be right up my ally though. I tried to check for codes with the key and found that the CEL don't come on....at all. Not on startup or when I try for trouble codes. I know it used to work! I don't see it Jus burning out without coming on since last time. More importantly, there are no codes shown on the odometer. Not even a 12. This leades me to believe the pcm is dead. I tried wiggling it while cranking but no changes at all. So I hooked up my lil OBD2 scanner that works with my phone.....it tells me that it can not connected to the ecu.

I'm not very handy with a multi meter either so I'm not sure exactly how to check the coil or ckp. Also in my reading I came to check the wiring at the O2 sensor after the cat and found the harness to be partially melted to the exhaust. Got it disconnected but still no CEL.

I'm leaning towards the pcm, but I always think worst case, I've never had an issue with it at all so that puts me on the fence about it.

Should I even bother checking the ignition coil and ckp, if so what's the best way.

Any other input or insite would be greatly appreciated.

ELMCZJ95 09-18-2013 05:51 PM

Fuel pump maybe?

AnotherRedZj 09-18-2013 05:57 PM

Quote:

Originally Posted by ELMCZJ95 (Post 16122593)
Fuel pump maybe?

sry a.d.d. got me again.

i tried priming the TB first before i F'd with any wires. no go.

thanx though:thumbsup:

Rich93ZJ 09-18-2013 06:57 PM

Check the fuse for your pcm (under the hood #20 iirc). If it is blown, check your O2 sensor wiring for a short then replace the fuse. Good luck

ZeeJay1997 09-18-2013 07:31 PM

Quote:

Originally Posted by rich93zj (Post 16124801)
check the fuse for your pcm (under the hood #20 iirc). If it is blown, check your o2 sensor wiring for a short then replace the fuse. Good luck

^^
this

AnotherRedZj 09-18-2013 07:34 PM

ill get on that after work tomorrow. right now is drink beer and forget about about my 2 outa 3 vehicles being down:cheers2:

keep the info coming though fellas! thanks:2thumbsup:

stovie 09-18-2013 10:55 PM

Had this problem before, turned out a wire to the tranny was rubbing on the shift linkage and blew a fuse. It should be a 20 amp one in your fuse box!!

AnotherRedZj 09-19-2013 09:03 PM

Checked fuses and relays all good.

Next question.....how exactly do you check if your pcm is in fact dead?

ZeeJay1997 09-19-2013 09:09 PM

Since the CEL is not coming on and you found mangled o2 wires, and you cant find a blown fuse, the PCM is a likely suspect.

before you condemn it, disconnect both os2 sensors and the crank sensor, turn on the key and see if you get the cel and key on back.

if not, it may be time to throw in the towel and get a pcm.

AnotherRedZj 09-19-2013 09:11 PM

Quote:

Originally Posted by ZeeJay1997 (Post 16159281)
Since the CEL is not coming on and you found mangled o2 wires, and you cant find a blown fuse, the PCM is a likely suspect.

before you condemn it, disconnect both os2 sensors and the crank sensor, turn on the key and see if you get the cel and key on back.

if not, it may be time to throw in the towel and get a pcm.

I thought you would chime in here soon... You slowly becoming my hero!

.....and, will do. But I think I only remember there being one O2 sensor, that sound off to you?

ZeeJay1997 09-19-2013 09:13 PM

Quote:

Originally Posted by AnotherRedZj (Post 16159393)
But I think I only remember there being one O2 sensor, that sound off to you?

one on the manifold and one on the cat.

AnotherRedZj 09-19-2013 09:18 PM

Quote:

Originally Posted by ZeeJay1997 (Post 16159457)

one on the manifold and one on the cat.

Found it. But its not on the manifold, one before the cat and one after.

ZeeJay1997 09-19-2013 09:24 PM

ah, I'm stuck on 4.0s.

i dont know beans about a 5.2. i thought they had more than 2?

AnotherRedZj 09-19-2013 09:32 PM

Quote:

Originally Posted by ZeeJay1997 (Post 16159689)
ah, I'm stuck on 4.0s.

i dont know beans about a 5.2. i thought they had more than 2?

Jus the 2.

Disconnected both and the ckp...no cel. And for good measure I tried the obdII scanner......it can find the "ecu" as It calls it, I know, its the same thing.

ZeeJay1997 09-19-2013 09:46 PM

it's the luck of the draw when the o2 wires get shorted. if the heater voltage shorts to ground it just blows a fuse. that is the best case, anything else can blow the internal circuits.


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