STILL NO SPARK after multiple parts replaced - Jeep Cherokee Forum

Notices
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here XJ (84-01)
All OEM related XJ specific tech. Examples, no start, general maintenance or anything that's stock.
Sponsored by:
Sponsored by:

STILL NO SPARK after multiple parts replaced

Old 05-21-2016, 12:48 PM
  #1  
ace
Junior Member
Thread Starter
 
Join Date: Jun 2010
Location: Rockingham County, VA
Posts: 51
Year: 1996
Model: Cherokee
Engine: 4.0 I6
Default STILL NO SPARK after multiple parts replaced

Hello all,

I'm hoping that if I can solve this issue, this post will be helpful to all the readers of the forum. (I've looked at numerous posts today, and I haven't found a situation just like mine). So here it goes.

The backstory: '96 4.0 XJ has been running perfectly for a year or more. Drove home one night last week and parked it. Next morning tried to start it: she cranks forever, but will not start. (On the bright side, it was in my driveway).

Tested for spark that night and had none.

I've replaced:
(In the last 3 months):
distributor cap
rotor
spark plugs
spark plug wires

(In the last week):
ignition coil
CPS (crankshaft position sensor)
pickup coil

I know many of us have had no-start issues; has anyone with a similar problem found another solution? Thanks.

Last edited by ace; 05-21-2016 at 12:51 PM.
ace is offline  
Old 05-21-2016, 04:14 PM
  #2  
Senior Member
 
Join Date: Nov 2013
Location: Lapeer, Murder Mitten
Posts: 773
Year: 2000
Model: Cherokee
Engine: 4.0 I6
Default

Do rotor and cap still look good? Did you use quality parts or cheapest available?
Pull coil wire from cap and check for spark from it.
Larry's XJ is offline  
Old 05-21-2016, 06:01 PM
  #3  
ace
Junior Member
Thread Starter
 
Join Date: Jun 2010
Location: Rockingham County, VA
Posts: 51
Year: 1996
Model: Cherokee
Engine: 4.0 I6
Default

Both cap and rotor are in great shape. I used parts priced "in the middle" mostly. No spark from the coil.
ace is offline  
Old 05-21-2016, 06:06 PM
  #4  
Junior Member
 
Jds12's Avatar
 
Join Date: Nov 2012
Location: St. Augustine, FL
Posts: 80
Year: 1999
Model: Cherokee
Engine: 4.0
Default

Had a '98 at work, would crank forever but no spark. We tried a few parts that commonly fail, tested parts etc, still zero spark.

Ended up buying a used ecm computer and it fired right up.
Jds12 is offline  
Old 05-21-2016, 06:13 PM
  #5  
ace
Junior Member
Thread Starter
 
Join Date: Jun 2010
Location: Rockingham County, VA
Posts: 51
Year: 1996
Model: Cherokee
Engine: 4.0 I6
Default

Thanks, Jds12. I have a feeling it's the computer. Especially with how it was working great and then just wouldn't fire up the next morning.

Has anyone had luck reprogramming a computer?
ace is offline  
Old 05-21-2016, 07:47 PM
  #6  
CF Veteran
 
Join Date: Nov 2010
Location: In the middle of Minnesota!
Posts: 5,572
Year: 1999
Model: Cherokee
Engine: 4.0
Default

ASD circuitry and ignition switch still in play as well as computer. First thing I would try is to swap the ASD relay in the PDC (black box under hood) with another non-critical relay. Good luck and keep us posted!
-------------------------------------------------------------

Spark: 12 volts from ignition switch to the ASD relay; when the key is first turned on the PCM provides a ground to the ASD relay to energize it, then the ASD relay passes 12 volts to the coil primary side. If no crank sensor signal is generated after a couple of seconds the PCM cuts the ground to the ASD relay (and fuel pump relay too) and that cuts power to the coil (and fuel pump). Key to START and once again the PCM energizes the ASD relay. Now, a critical element is the crank sensor--no signal from the crank sensor and the PCM won't trigger the coil to provide spark.
tjwalker is offline  
Old 05-22-2016, 01:34 PM
  #7  
ace
Junior Member
Thread Starter
 
Join Date: Jun 2010
Location: Rockingham County, VA
Posts: 51
Year: 1996
Model: Cherokee
Engine: 4.0 I6
Default

Update:
Swapped out the ASD relay with another one. No fix.

We're gonna solve this!
ace is offline  
Old 05-22-2016, 01:41 PM
  #8  
CF Veteran
 
madmanmarty's Avatar
 
Join Date: Jun 2014
Location: PA
Posts: 1,052
Year: 1994
Model: Cherokee
Engine: 4.0 HO
Default

are you sure it is a strong spark?
what brand of crank sensor?
others, does a bad cam sensor cause a no spark?
madmanmarty is offline  
Old 05-22-2016, 03:09 PM
  #9  
ace
Junior Member
Thread Starter
 
Join Date: Jun 2010
Location: Rockingham County, VA
Posts: 51
Year: 1996
Model: Cherokee
Engine: 4.0 I6
Default

There is no spark at all.
ace is offline  
Old 05-22-2016, 06:40 PM
  #10  
CF Veteran
 
Join Date: Nov 2015
Location: syracuse ny
Posts: 1,523
Year: 1997
Model: Grand Cherokee
Engine: 4.0
Default

cam and crank sensors both can cause no start. B+ to all your sensors? fried wire under hood? Ground to all sensors?
97grand4.0 is offline  
Old 05-22-2016, 10:14 PM
  #11  
Senior Member
 
BillyBoy's Avatar
 
Join Date: Aug 2009
Location: Detroit, Michigan
Posts: 960
Year: 1998
Model: Cherokee
Engine: 4.0
Default

My standby answer to no start once all grounds are cleaned and minor parts replaced is to start wiggling. Have someone crank it. Put on a leather glove. Beware of moving parts like fan blades...

While it's being cranked, start wiggling wires, harnesses, and especially connections. I replaced my coil and all the regular tune up stuff and it turned out being a worn wire at the coil. Held at the right angle, fired right up. Next time was the wiring harness that runs across the inside of the firewall at the top. Wiggle hard, all directions.

Good luck. (At least my way of trying get is also cheap.)
BillyBoy is offline  
Old 05-23-2016, 12:00 AM
  #12  
CF Veteran
 
Join Date: Apr 2012
Location: Wisconsin
Posts: 5,302
Model: Cherokee
Default

You should have +12V at the coil (+) terminal when the ASD relay is energized. (for at least a few seconds after starting to crank the engine) Check to see if you do.
(This is the two-wire connector to the coil, not the high voltage lead to the cap)

The other wire in that connector is the (-) and it's grounded by the PCM to trigger the spark.
You can probe with a test light to see if it strobes when the engine cranks. If not there's a problem with the ECU signal. Check the three connectors and ground connections before condemning it.

Last edited by Radi; 05-23-2016 at 12:03 AM.
Radi is offline  
Old 05-24-2016, 10:31 AM
  #13  
Newbie
 
Join Date: Jul 2013
Location: North AL
Posts: 18
Year: 1998
Model: Cherokee
Engine: 4.0L
Default

Check the pcm fuse in the PDC under the hood. Mine kept blowing due to a short - took forever to find that the fuse was the issue, but same symptoms as you. chafed wire rubbing on the block sparked and shut it off...
JW
jawalter is offline  
Old 05-24-2016, 06:01 PM
  #14  
Senior Member
 
BillyBoy's Avatar
 
Join Date: Aug 2009
Location: Detroit, Michigan
Posts: 960
Year: 1998
Model: Cherokee
Engine: 4.0
Default

May be a silly question, but how did you check the spark?
BillyBoy is offline  
Old 05-30-2016, 08:22 AM
  #15  
ace
Junior Member
Thread Starter
 
Join Date: Jun 2010
Location: Rockingham County, VA
Posts: 51
Year: 1996
Model: Cherokee
Engine: 4.0 I6
Default

I pulled the spark plug wire off cylinder 1, put a used plug in it (one that was still in pretty decent shape - no corrosion/charring), laid the plug across the valve cover, and had a friend crank it while I looked for spark. Tried this twice.

Here's my silly question: the valve cover is a ground source, right?
ace is offline  

Thread Tools
Search this Thread
Quick Reply: STILL NO SPARK after multiple parts replaced


Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description: