98 GC 4.0 No Spark - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Grand Cherokee & Commander Forums > ZJ Grand Cherokee Forum > 98 GC 4.0 No Spark

Jeep LED Light Lights! OCONEE OFF-ROAD 706-534-9955Ledlight bar light locks @ oconee off road 706 534 9955Introducing MONSTALINERô UV Permanent DIY Roll On Bed Line

Reply
Unread 07-10-2012, 09:08 AM   #1
FLSnake
Registered User
 
Join Date: Jun 2012
Location: Bradenton, FL
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   Reply With Quote
Unread 07-10-2012, 10:50 AM   #2
FLSnake
Registered User
 
Join Date: Jun 2012
Location: Bradenton, FL
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   Reply With Quote
Unread 07-10-2012, 10:52 AM   #3
JustN11
Registered User
1997 ZJ 
 
Join Date: Jun 2012
Posts: 222
Try checking the IAC
JustN11 is offline   Reply With Quote
Unread 07-10-2012, 12:00 PM   #4
FLSnake
Registered User
 
Join Date: Jun 2012
Location: Bradenton, FL
Posts: 7
Quote:
Originally Posted by JustN11 View Post
Try checking the IAC
Is there a procedure to check it?
FLSnake is offline   Reply With Quote
Unread 07-10-2012, 12:14 PM   #5
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   Reply With Quote
Unread 07-10-2012, 12:53 PM   #6
melk
Registered User
1996 ZJ 
 
Join Date: Sep 2009
Location: Charlotte, NC
Posts: 2,891
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   Reply With Quote
Unread 07-11-2012, 04:30 AM   #7
FLSnake
Registered User
 
Join Date: Jun 2012
Location: Bradenton, FL
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   Reply With Quote
Unread 07-11-2012, 05:53 AM   #8
melk
Registered User
1996 ZJ 
 
Join Date: Sep 2009
Location: Charlotte, NC
Posts: 2,891
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   Reply With Quote
Unread 07-15-2012, 05:26 AM   #9
FLSnake
Registered User
 
Join Date: Jun 2012
Location: Bradenton, FL
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   Reply With Quote
Unread 07-15-2012, 01:00 PM   #10
coralman
Web Wheeler
 
coralman's Avatar
1998 ZJ 
 
Join Date: Jul 2010
Location: florida
Posts: 4,221
Did you disconnect the battery when installing the sensor? Almost sounds like a bad coil driver. Any codes?
__________________
Move over bear.I'm tired of working on the jeep
coralman is offline   Reply With Quote
Reply
Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.