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General Forums => The Mess Hall => Topic started by: badbowtie on August 31, 2007, 07:38:22 AM

Title: 97 wrangler running rough? help
Post by: badbowtie on August 31, 2007, 07:38:22 AM
 :confused:

Ok in the mornings my 97 wrangler runs rough when first put it gear. seems like it wants to die, give it some some gas its sputters and goes then great for the whole day.   

just replaced plugs (gapped correctly)
wires
cap and rotor.

any others?

thanks,
Nick
Title: Re: 97 wrangler running rough? help
Post by: dunklervogel on August 31, 2007, 11:34:14 AM
Clean out the throttle body and check your air filter.  Make sure the sensors on the throttle body are cleaned up and there is no gunk.  Any CEL codes being thrown?
Title: Re: 97 wrangler running rough? help
Post by: jcoleman on August 31, 2007, 11:46:15 AM
I have a similar problem.  And I'm not mechanically inclined by any means. So what are CEL codes?
Title: Re: 97 wrangler running rough? help
Post by: chardrc on August 31, 2007, 11:47:58 AM
CEL= check engine light. on the newer jeeps you can turn the key on and off a few times and it will display them for you. if you do a search of the forum the instructions are round somewhere
Title: Re: 97 wrangler running rough? help
Post by: jcoleman on August 31, 2007, 12:39:46 PM
I actually have that problem.  For a while my airbag light would stay on (hasn't in a while), and my left turn signal would stay green (does that currently).  It comes and goes.  I thought maybe it was a grounding problem, but I'm not really sure.
Title: Re: 97 wrangler running rough? help
Post by: Jeffy on August 31, 2007, 06:09:20 PM
How to recover CEL codes - http://4bangerjp.com/forums/index.php?topic=3419
Title: Re: 97 wrangler running rough? help
Post by: jcoleman on August 31, 2007, 11:51:04 PM
thanks jeffy, I'll try that out tomorrow.
Title: Re: 97 wrangler running rough? help
Post by: jcoleman on September 01, 2007, 07:39:20 AM
Unfortunately I didn't get a chance to find that out today because I had to go to work.  However I found out a new problem.  For the past few days my jeep has not been starting up right away.  I'll get in turn the key, and nothing happens, try it again hold it a little longer and either it fires up, or I try it again.  Today was the worst though, I couldn't get it started for Five minutes or so.  I thought it was my battery at first, but when it started right up like 50th time, I decided that was probably not the case.  Also I hate to mention it, because I hate for this to be my fault, But I was being a little adventurous the other and decided to try and start my tj by popping the clutch.  Well it didn't work because I don't think I had enough speed, but After that my jeep hasn't started correctly. 

P.S. I won't be trying to start my jeep without the battery unless it is an absolute emergency, like a terrorist attack.

 :confused:
Title: Re: 97 wrangler running rough? help
Post by: chardrc on September 01, 2007, 05:03:26 PM
i jsut had to push start my jeep a week ago(darn battery died) but it in 4th and had my dad push me down the street and it started right up....minus it being in too high a gear so it sounded real rough tell i pushed in the clutch :uhoh:. and that didn't effect my yj...
Title: Re: 97 wrangler running rough? help
Post by: Jeffy on September 01, 2007, 05:49:55 PM
When starting are you letting the fuel pump prime?  You'll hear a buzzing sound when you turn the key to ON.  Then it should start right off.  I don't think there should be any problems with push starting it.  I've done it several times with no problems.  Just make sure you go into 2nd.

You really should check for CEL codes.  It will help you pinpoint the problem(s).
Title: Re: 97 wrangler running rough? help
Post by: jcoleman on September 01, 2007, 11:31:43 PM
yea, it does make that buzzing sound.  I'll see if letting it prime will do the trick. 
Title: Re: 97 wrangler running rough? help
Post by: jcoleman on September 02, 2007, 10:48:19 PM
ok so the code numbers that came up are, 12 and 55.  I looked those up and they don't seem to be big problems, Am I right?
Title: Re: 97 wrangler running rough? help
Post by: Jeffy on September 03, 2007, 12:05:33 PM
ok so the code numbers that came up are, 12 and 55.  I looked those up and they don't seem to be big problems, Am I right?

Yeah, 12 is the disconnected battery.  You might even get a 33 if you don't have A/C. Then 55 is the end code.

for both the OP and you; If you let it idle rough, do you know if it will clear up when the engine warms up?  If it does then I'd suspect the ASI motor since that allows air to bypass the throttle plate until the engine warns up enough to not need the choke open.

And for jcoleman's additional problem, I would maybe look at the Crank Position sensor.  It could be fouled or just getting old and is failing.  Although if it fails completely the engine won't start.  Sometimes it allows a start then will cut out later on.

Also, if you push start the Jeep does it start up right away?


(Besure to test before replacing parts since it's difficult to trouble shoot over the Internet and you don't want to be throwing money at it.)
Title: Re: 97 wrangler running rough? help
Post by: jcoleman on September 04, 2007, 03:44:32 PM
Here's the scoop.  The starting problem is only when it sits overnight or for extended periods of time.  I've let it prime but still nothing it still takes 5, 6, 15 tries to get it started.  And usually in the morning there is a delay from the time that I turn the key to the time it actually cranks up. Meaning I'll turn the key hold it there for a second and then it comes to life, just to shut off again. At which point I start it up again give it some gas, it spudders for a second then roars up and settles at about 600rpm.  After driving it around for a while I can let it sit for 5 hours and come back out and it starts right up.

Also, what exactly should I be looking for if my ASI motor and Crank Position Sensor are faulty?  How might I test so to speak.  (I'm really not that mechanically inclined. I like doing stuff with my hands, and like working on cars, but the problem is I just don't know enough yet to be confident working on them.)

With the information I just provided is there anything else that might be adding to this?  I also cleaned out my throttle body (nothing really there) and checked my air filter (no problem there either), and checked for gunk on the throttle body sensors (just some dust on the outside).

Thanks for all your patience with me, especially Jeffy.  I've learned a lot even if I haven't figured out a solution to the problem(s).
Title: Re: 97 wrangler running rough? help
Post by: Jeffy on September 04, 2007, 05:05:46 PM
The not starting when sitting for a while really makes me think it might be a fuel pump issue.  Might want to check the fuel rail pressure and see if it's making enough pressure, since it sounds like it runs fine when it does run.
Title: Re: 97 wrangler running rough? help
Post by: spoonman on September 13, 2007, 09:09:44 AM
just had a bud with the same problem in his 97. jeffy is right on. until the fuel pump craps out, just turn the key on and wait until u hear the pump prime. then start.
Title: Re: 97 wrangler running rough? help
Post by: jcoleman on September 13, 2007, 11:45:59 PM
update.  The problem has subsided... for now.  When it was not working properly I would wait for the pump to prime, and that didn't do anything.  it was all just kinda well random.  But for the past week or two the problem has not returned.  I need to get it inspected soon, So i'm making a list of things they might also check out. 

I'm still a bit confused why it may have come and gone.  Probably is the fuel pump, I just haven't gotten around to checking the pressure since it's now working properly.
Title: Re: 97 wrangler running rough? help
Post by: damon54 on September 14, 2007, 06:01:35 AM
I don't know if there were any recalls on it, but the 96 model cherokees have all kinds problems with the fuel pump.  Apparently Jeep lined the fuel tank with a substance that starts to break down after a few years that would get into the fuel pump and gum it up.  I don't know if that was a problem with the Wranglers or not.  If you google it you may find articles from people with similar problems.  Thats how I found out about the cherokee.