98 GC 4.0 No Spark - JeepForum.com
 
LinkBack Thread Tools
post #1 of 10 Old 07-10-2012, 09:08 AM Thread Starter
FLSnake
Registered User
 
Join Date: Jun 2012
Location: Bradenton
Posts: 7
98 GC 4.0 No Spark

I have a 98 Grand Cherokee 4.0 2WD, it would start and run for about 30 sec then sputter and die, if I kept it accererated manually at about 1200 RPM it would continue to run ok until i allowed it to idle and again it would sputter and die, sometimes continue sputtering after the key was off also.
Sometimes it would start right back up and other times it would crank and crank and eventually start.

I changed the crank sensor and it did the same thing.

Now it will only crank, no fire, I am getting good fuel pressure when I turn the key on and it continues good as i crank.

I am getting no spark at the plug wires and no spark from the coil wire.

I put a volt meter on the 2 wire connector that feeds the coil and when I turn the key on i get a 12 volt spike then it drops to zero, as i crank i get variable readings from about .10 to .23, no where close to even one volt.

Any thoughts would be appreciated.

FLSnake is offline  
Sponsored Links
Advertisement
 
post #2 of 10 Old 07-10-2012, 10:50 AM Thread Starter
FLSnake
Registered User
 
Join Date: Jun 2012
Location: Bradenton
Posts: 7
Just an update...

I took out the new Crank Sensor and put the old one back in and now it will start but still has same original issues, I must have cooked the new crank sensor.
FLSnake is offline  
post #3 of 10 Old 07-10-2012, 10:52 AM
JustN11
Registered User
1997 ZJ 
 
Join Date: Jun 2012
Posts: 222
Try checking the IAC
JustN11 is offline  
post #4 of 10 Old 07-10-2012, 12:00 PM Thread Starter
FLSnake
Registered User
 
Join Date: Jun 2012
Location: Bradenton
Posts: 7
Quote:
Originally Posted by JustN11 View Post
Try checking the IAC
Is there a procedure to check it?
FLSnake is offline  
post #5 of 10 Old 07-10-2012, 12:14 PM
JustN11
Registered User
1997 ZJ 
 
Join Date: Jun 2012
Posts: 222
Well, I've never had IAC problems (knock on wood) but I've heard that you can hear it work. You could try to listen for it. The IAC has a pair of solenoids that make a noise when working. You'll need a stethoscope to hear it though. You might try unscrewing the 4 bolts that hold it down 1/8" and see if that makes a difference as well. There are quite a few threads on here that talk about diagnosing IAC problems. I would search "Idle Air Controller" on here and see if one of those threads could give you a better understanding of how to diagnose it.
JustN11 is offline  
post #6 of 10 Old 07-10-2012, 12:53 PM
melk
Registered User
1996 ZJ 
 
Join Date: Sep 2009
Location: Charlotte
Posts: 2,890
How old is your battery? It's surprising the wonky effects a weak battery will have on the behavior of the Jeep.
melk is offline  
post #7 of 10 Old 07-11-2012, 04:30 AM Thread Starter
FLSnake
Registered User
 
Join Date: Jun 2012
Location: Bradenton
Posts: 7
Quote:
Originally Posted by melk View Post
How old is your battery? It's surprising the wonky effects a weak battery will have on the behavior of the Jeep.
The battery is about 1 1/2 years old, I could have it tested.
FLSnake is offline  
post #8 of 10 Old 07-11-2012, 05:53 AM
melk
Registered User
1996 ZJ 
 
Join Date: Sep 2009
Location: Charlotte
Posts: 2,890
A general note on Sensors, they seem not to like Bosch. BorgWarner (BWD) or NTK/NGK seem to work ok, or of course OEM/Mopar.

I would make sure to check and clean the IAC as well, since that will present problems with idle.
melk is offline  
post #9 of 10 Old 07-15-2012, 05:26 AM Thread Starter
FLSnake
Registered User
 
Join Date: Jun 2012
Location: Bradenton
Posts: 7
Quote:
Originally Posted by melk View Post
A general note on Sensors, they seem not to like Bosch. BorgWarner (BWD) or NTK/NGK seem to work ok, or of course OEM/Mopar.

I would make sure to check and clean the IAC as well, since that will present problems with idle.
The new crank sensor I bought was a BWD, would the IAC cause the hard start also? Sometimes it cranks on and on before it will restart.
FLSnake is offline  
post #10 of 10 Old 07-15-2012, 01:00 PM
coralman
USER OF PARTS CATALOGS
 
coralman's Avatar
1998 ZJ 
 
Join Date: Jul 2010
Location: florida
Posts: 7,085
Did you disconnect the battery when installing the sensor? Almost sounds like a bad coil driver. Any codes?

Info on projects and repairs categorized by system
http://www.jeepforum.com/forum/f13/c...-faqs-2863665/

Originally Posted by HighLonesome
lol...if life is as a simple as a 5.9 making you happy, I'd say go ahead and buy it on impulse. ZJs are the way of Zen. Wax on, wax off
coralman is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.



Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
no spark to spark plugs??? jeepgcnp ZJ Grand Cherokee Forum 4 11-27-2011 09:08 PM
spark @ coil, no spark @ plugs 94GC52 ZJ Grand Cherokee Forum 4 07-09-2009 06:17 PM
no spark Brian93YJ ZJ Grand Cherokee Forum 8 01-06-2008 11:20 AM
93 4.0 GC - No Spark Rockdaddy ZJ Grand Cherokee Forum 3 11-20-2007 07:46 PM
No spark? dcgoff ZJ Grand Cherokee Forum 4 05-27-2005 05:25 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome