Forum Index
Jeep Horizons HomeLinksJeep Horizons Tech Write-upsJeep newsLand useContact

 Watched TopicsWatched Topics   FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Cherokee hard to start


 
Post new topic   Reply to topic     Forum Index -> Cherokee Forum
View previous topic :: View next topic  
Author Message
Gryphon
Member


Joined: 29 Jan 2006
Location: Platteville, WI

PostPosted: Sun Jan 29, 2006 8:41 pm    Post subject: Cherokee hard to start Reply with quote

This is my first post, but I've searched the site and couldn't find an answer to my question. I have a 98 Cherokee sport and it has a wierd problem. If it is cold, it starts fine. If it is warm (it has been running in the last 1/2 hour) it starts fine. Anything in between that it is hard to start. It turns over fast, but it will not start unless I engage the starter, let off for a second and engage the starter again. I've replaced the plugs and wires and the air cleaner. I checked the self diagnostics and nothing comes up. I don't want to keep guessing what is wrong and buying parts to see if it will work. I'm hoping that you guys have some suggestions of what I should do next. Any ideas?
Back to top
View user's profile Send private message Yahoo Messenger
Lowrider
Member


Joined: 08 Nov 2005
Location: Washington State

PostPosted: Sun Jan 29, 2006 8:44 pm    Post subject: Reply with quote

My '97 Cherokee acted the same way. It got harder and harder to start until it finally just quit running one day as I was driving down the street. Turned out to be the crank-position sensor.
_________________
She was only a fisherman's daughter,
But when she saw my rod she reeled.


2006 Wrangler Unlimited
1997 Cherokee Sport 2WD
Back to top
View user's profile Send private message
Gryphon
Member


Joined: 29 Jan 2006
Location: Platteville, WI

PostPosted: Mon Jan 30, 2006 9:25 am    Post subject: Reply with quote

Did you replace the sensor yourself? If so, can you tell me where it is and if there is a way I can test it? Thanks for the help.
Back to top
View user's profile Send private message Yahoo Messenger
Lowrider
Member


Joined: 08 Nov 2005
Location: Washington State

PostPosted: Mon Jan 30, 2006 9:55 am    Post subject: Reply with quote

No, I didn't do the work myself. I had to have it towed to the dealership and they diagnosed it and replaced the sensor.

They are easy to replace if you could be sure that's what the problem is. It threads into the engine near the bottom of the timing cover.

My trouble began just like yours, where it wouldn't start on the first try no matter how long I cranked it. But turn the key off, wait a few seconds, hit it again, and it would start right up. It progressed from there to where I'd half-drain the battery trying it again and again until it finally fired up.

Then it just started working normally again, starting immediately without problems for a couple of months, and one day as I was slowing to pull into a parking space it quit running, just like I'd shut off the ignition, and it absolutely wouldn't start again, even after I left it for several hours before trying it again. The next stop was the shop.

I believe they charged me about $150 for the sensor and another hundred and some to do the diagnostic work and the actual sensor replacement. Total bill was a little over $300.
_________________
She was only a fisherman's daughter,
But when she saw my rod she reeled.


2006 Wrangler Unlimited
1997 Cherokee Sport 2WD
Back to top
View user's profile Send private message
Gryphon
Member


Joined: 29 Jan 2006
Location: Platteville, WI

PostPosted: Mon Jan 30, 2006 3:40 pm    Post subject: Reply with quote

That sure sounds like it could be the problem. I wish that there was a way to test the sensor. I would gladly pay the $150 for the sensor if I were sure it was the culprit. The only thing that bothers me is that there is an error code for a bad crank sensor, but my Jeep isn't showing it. Maybe I'll just take the sensor off and see if I can clean up the contacts.
Back to top
View user's profile Send private message Yahoo Messenger
JeepinNH
Member


Joined: 13 Sep 2005
Location: New Hampshire

PostPosted: Mon Jan 30, 2006 8:14 pm    Post subject: sensor Reply with quote

I had a similiar issue with my Grand Cherokee but it was the one in the distributer. From what I remember the 4.0 has 2 of these hall effect type sensors. I was able to check mine with a volt meter. The old Hanes manual actually listed how to test it. Basically 5volts and 0 volts while the engine is turning. Mine was stuck in the middle somewhere, at least when it wouldn't start. It was a painless replacement that cost about $60 for the part.
_________________
Mike

Present: 99 Cherokee
Past: 86, 87 Cherokee; 94 Grand Cherokee
Back to top
View user's profile Send private message
Gryphon
Member


Joined: 29 Jan 2006
Location: Platteville, WI

PostPosted: Wed Sep 06, 2006 2:59 pm    Post subject: Reply with quote

Could you elaborate on how to test the sensors? I have a voltmeter but no hayes manual. This problem hasn't gotten any worse, but it hasn't gotten any better. I fear that one day it's just gonna quit and strand me somewhere. I'll probably replace the CPS since that seems to be a problem on a lot of high milage 4.0's Before I do that though, I want to test the dist sensor.
Back to top
View user's profile Send private message Yahoo Messenger
ThePhantum
Pissed-Off Admin
Pissed-Off Admin


Joined: 23 Jan 2004
Location: I knew it...I'm surrounded by Assholes!

PostPosted: Wed Sep 06, 2006 4:55 pm    Post subject: Reply with quote

It sounds like you have a classic CPS problem. If the reference signal for either the crank or cam position sensor shorts to ground, the PCM will go into a safeguard routine and shut down to protect itself. Since the PCM is now essentailly turned off it will not store a fault code (DTC). Even if the short is momentary, the engine will not start until the ignition is cycled back to the LOCK postion, resetting the PCM.

The test for both the the crankshaft and camshaft position sensors are the same. With the engine cranking, check the voltage from the orange wire to ground. The voltmeter reading should cycle from 0 volts to about 5 volts. If it doesn't cycle, the sensor is bad. If you're using a digital voltmeter, crank the engine a very small amount at a time. Digital meters do not react instantly, so it's tough to see the change in reading if the engine is cranked continually.

However, this only works if you can test for the problem while it's happening. Most CPS problems manifest themselves as momentary shorts and will test good the rest of the time.
_________________

97 XJ Sport with a bunch of stuff
Quote:
Never argue with idiots, they drag you down to their level and beat you with experience
Back to top
View user's profile Send private message AIM Address Yahoo Messenger MSN Messenger
Gryphon
Member


Joined: 29 Jan 2006
Location: Platteville, WI

PostPosted: Wed Sep 06, 2006 7:50 pm    Post subject: Reply with quote

I tested the sensors and they seemed to be working fine. I would get both 5 and 0 volts. Nothing in between. But, this problem doesn't always happen. Sometimes the Jeep starts just fine. What should I do? What is the most likely culprit? What should I spend my money on first?
Thanks.
Back to top
View user's profile Send private message Yahoo Messenger
ThePhantum
Pissed-Off Admin
Pissed-Off Admin


Joined: 23 Jan 2004
Location: I knew it...I'm surrounded by Assholes!

PostPosted: Wed Sep 06, 2006 8:40 pm    Post subject: Reply with quote

The most likely culprit is the Crank Position Sensor for the reasons stated above. Based on your description, they exactly match the symptoms you are seeing.
_________________

97 XJ Sport with a bunch of stuff
Quote:
Never argue with idiots, they drag you down to their level and beat you with experience
Back to top
View user's profile Send private message AIM Address Yahoo Messenger MSN Messenger
Gryphon
Member


Joined: 29 Jan 2006
Location: Platteville, WI

PostPosted: Thu Sep 07, 2006 5:51 am    Post subject: Reply with quote

From what I've read, you're a guy who knows his stuff. Crank sensor it is then. I'll replace it this weekend and post the results.
Thanks
Back to top
View user's profile Send private message Yahoo Messenger
Gryphon
Member


Joined: 29 Jan 2006
Location: Platteville, WI

PostPosted: Wed Sep 20, 2006 5:29 am    Post subject: Reply with quote

I replaced the crank sensor and it wasn't the problem. My father in law has a good friend that owns a shop and offered to have a look at it. It turns out that there are parts in my fuel pump that are going out. There is something like a check valve that is supposed to hold pressure in the fuel lines even while the Jeep sits. Mine takes about 2 hrs for the pressure in the fuel line to drop to zero. It would cost me about $350 to buy a new fuel pump, but my FIL's friend said that he would just live with it. It shouldn't cause any more problems and there's no reason to believe that it will strand me somewhere. I just thought I'd let you guys know what I found in case anyone else were having the same problem.
Back to top
View user's profile Send private message Yahoo Messenger
Display posts from previous:   
Post new topic   Reply to topic     Forum Index -> Cherokee Forum All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Visit links4jeeps.com for write-ups, forums and clubs




Jeep®, Wrangler, Cherokee, Liberty and Grand Cherokee are copyrighted and trademarked to Chrysler LLC.
jeephorizons.com is not in any way associated with or endorsed by the Chrysler LLC.
All other content is copyright Jeep Horizons 2004-2008.
Tech write-ups Links Discussion board Land use News Site Map Terms of Use

Powered by phpBB © 2001, 2005 phpBB Group