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-   -   really, what is this? (http://www.jeepforum.com/forum/f13/really-what-1547951/)

2tall2slow 07-11-2013 11:10 PM

really, what is this?
 
getting a bit frustrated and need some insight. 98 jgc 208k miles, wants to sputter and stall while driving. very randomly. check engine light isnt on, lately abs light will show itself and go off. now i have read almost everything on the topic. ignition coils, plugs wires..money pit. i did replace rotorbutton and cap, along w o2 sensors. instead of replaceing every switch and sensor known, shouldnt i look closer at pcm? tried the screw trick. no good. loose connection to pcm cause it to kick and shut off randomly? i got a wife and kids who frequently ride in this thing, and i havent got much money. suggestions welcomed. thanks jeep family. rbo:mad

AaronButler 07-11-2013 11:14 PM

check/do the free and cheap things first. check your spark plugs, clean your IAC (dont forget the housing) and throttle body. check for a clogged air filter and that you are getting stable fuel pressure.

dellis 07-11-2013 11:22 PM

I can give you some guidance. And if you are handy with tools and a multimeter, you will soon be able to diagnose and repair your stalls. But, first please tell me any patterns that you are noticing with the stuttering stalls.

(1) Cold or hot engine, or both?
(2) Have you noticed it happening more with cold weather or hot weather, or a specific temperature range?
(3) Does it happen at all speeds, including idling?
(4) Does it happen in gear and in neutral, or only in gear?
(5) Does it have an occasional no-start condition that eventually corrects itself?
(6) Any backfires through the exhaust, or any odd smells during stalls?
(7) And, most importantly, have you read any codes from your Jeep using an OBDII Scanner? If not, get over to an Advance Auto or someplace like that and borrow their tool to see if you have any codes. (Yes, it can contain codes EVEN if the CEL is not illuminated).

When you respond, this will help us to narrow down and diagnose your problem in a methodical way whereby you won't be just guessing, tossing parts at the problem, hoping, and then getting disappointed.

ZeeJay1997 07-12-2013 05:55 AM

deleted post

ZeeJay1997 07-12-2013 05:58 AM

Quote:

Originally Posted by 2tall2slow (Post 15668095)
shouldnt i look closer at pcm?

Maybe, if you've eliminated the easy stuff. See link in my sig. It is routine maintenance that doesn't cost much, if anything.

looks like you may be on phone so here's the link http://www.jeepforum.com/forum/f13/1...l#post14045654

2tall2slow 07-12-2013 07:24 AM

well it usually kicks and tugs when engine is warm. rpms go wild then to zero while driving, after a few seconds it catches itself and comes back on. last night, with kids, it dies while at a red light and abs flashed and went off. i put in park and cranked it right back up fine. 3 days ago w no cel on a friend scanned it. all it told him was low battery voltage. battery was bought new a month ago. i dont believe weather plays apartcin it but it might. been raining all month tempa avg 80-85.

Kevinyj95 07-12-2013 08:17 AM

Well I would clean the connector at the pcm with spray and add a dielectric grease. Most of the time this fixes something. Unbolt and wire brush all grounds and apply grease. clean the TB with some carb cleaner. Get a electrical guage and check the batt while running. See what the charging system is putting out. You most likely have a corroded connection somewhere. Check for vacuum leaks. Then go from there. Get all the little problem solvers out of the way and go from there.

Kevinyj95 07-12-2013 08:19 AM

Make sure to clean the IAC and TPS.

dellis 07-12-2013 09:03 AM

Quote:

Originally Posted by 2tall2slow (Post 15668597)
well it usually kicks and tugs when engine is warm. rpms go wild then to zero while driving, after a few seconds it catches itself and comes back on. last night, with kids, it dies while at a red light and abs flashed and went off. i put in park and cranked it right back up fine. 3 days ago w no cel on a friend scanned it. all it told him was low battery voltage. battery was bought new a month ago. i dont believe weather plays apartcin it but it might. been raining all month tempa avg 80-85.

Low battery voltage can play havoc with your PCM and other car electronics. What voltage are you noticing from your dashboard gauge before starting (key on) and while running? Also, have you noted your voltage reading during a stall?

Finally, when you mention that your RPM goes wild, do you mean the gauge goes wild (but the actual RPMs remain steady and the Jeep drives normally) or that the actual RPMs are going wild? Are other dash gauges erratic, or just the RPM?

The code + ABS warning + wildly fluctuating RPM is iinitially leading me to suspect that you have a battery power problem. I would be interested to hear what is happening with your voltage meter on your dash, but if it is showing a low condition or an erratically low condition, then ZeeJay's link above to his dirty dozen has some excellent advice in #3, #4, and #5 that should be followed ... particularly regarding cleaning your battery & ground terminals.

2tall2slow 07-13-2013 04:01 PM

Well i replaced ignition coil today, plugs and wires. drove ok, so far.. its a random accurance when it happens. noticed volt gauge readsok when it kicks. cant find any corrosion anywhere, grounds look good. For now i will drive it and leave the wife and kids with my more dependable '94. wish me luck, and thanks very much for all the tips and advice! I'm new at mechanics and learning lots lately. i will keep u guys posted as to how it goes from here.

2tall2slow 07-15-2013 07:31 AM

Since i replaced my plugs and wires, ign coil its drove a good distance over two days. This morning i made it a quarter mile down the road and it kicks...then rpm hand jumps around..then jeep lost power. Cel came on so i came to a stop, put in park and re-cranked it. Started fine and got me home. Dirty dozen link was helpful, so after checking thru all of that, now what? Need a fix, spent my entire check, the family is in need of a solid ride. Any advice??

newfieZJ 07-15-2013 07:42 AM

You have a bad upstream 02 sensor .

TEST : Unplug it . Tie wrap it back from the exhaust . You will get a CEL but just ignore it for a few days . With the sensor unplugged , the PCM will use pre-set settings and not kick and stumble as you have described while unplugged .

99% sure this is indeed your issue .

Fix : Replace with Mopar part . I believe NTK/NGK would also be the same

2tall2slow 07-15-2013 07:56 AM

o2 sensor i replaced just days ago.. I believe i have two, the one on the exhaust just below the rear manifold is the one i replaced. Any other possibilities?

newfieZJ 07-15-2013 08:10 AM

Sorry , I missed that .

My only other advise is to pull and check the PCM connection . Even rejoining it can make it have better contact again . Do the same with all you fuses . Refresh the contacts . A little can go a long way .

By chance do you know what code came up with the CEL ?

2tall2slow 07-15-2013 09:02 AM

No code was read, cel doeant stay on cant get a reading. Pcm is what i plan on playin with next.


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