no spark,1990 cherokee sport 4.0l -

LinkBack Thread Tools
post #1 of 4 Old 04-25-2010, 10:35 PM Thread Starter
Registered User
1990 XJ Cherokee 
Join Date: Apr 2010
Location: Arvada,Co
Posts: 2
no spark,1990 cherokee sport 4.0l

Please help!ran fine the day before the problem but the next morning wouldn't start.just cranks over.I have already changed the cap,rotor,coil,icm,and cps.Could it be the ecm?Thanks in advance

mike13 is offline  
Sponsored Links
post #2 of 4 Old 04-25-2010, 11:36 PM
Registered User
1988 XJ Cherokee 
Join Date: Apr 2010
Location: WI
Posts: 187
Well, you should probably check all your grounds and connections. You've checked for spark and still nothing? If so, the neutral safety switch has been known to cause no-start situations. Try starting it in park and in neutral. Not sure if it's the nss or the cps that could start in N vs P.

Could it be a fuel issue? Maybe your pump is shot, something along those lines. Look up fuel pressure tests in your manual or online.
Or a preliminary test: I think you just pull the 4 bolts off the rail, wiggle the injectors loose without turning them too much. Then you would find something to catch the fuel spray with (*Fire extinguisher handy) and turn it over. Pretty sure all should spray at first.
If that's good: do your pressure test.
If that's bad: probably fuel pump.

Whenever you remove the injectors it's a good idea to replace the o-rings. Leaky fuel obviously a major fire hazard. O-ring kits are under 15 bucks- 2 rings per injector and one or more for the pressure regulator which you probably wouldn't need to mess with. My manual says to use the black/brown o-rings on specific ends of the injectors, but my kit came with all brown o-rings which is just fine. Use Vaseline on the rings to seat them. Helps you install without any damage and will get eaten away by fuel with no adverse effects.
HenryKrinkle is offline  
post #3 of 4 Old 04-26-2010, 04:49 PM
Registered User
Join Date: Dec 2004
Posts: 8
Hi, to add a little info, this jeep is a manual transmission and there is fuel pressure. He also just tried a different ECM with no luck. Seems to be getting fuel just not igniting it.

Any other ideas?
aviat0r is offline  
post #4 of 4 Old 04-27-2010, 05:30 PM Thread Starter
Registered User
1990 XJ Cherokee 
Join Date: Apr 2010
Location: Arvada,Co
Posts: 2
i had it towed to a shop and they discovered that when i replaced the cap i was one off on the wires.runs fine now but i feel like a *******.I asked them about the spark problem and they said it was probably the crank sensor.I replaced the cap before the crank sensor so that is why it didn't start.Thanks for your help!
mike13 is offline  

Quick Reply

Register Now

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

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


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

Email Address:


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
1990 Cherokee, no spark Leobram XJ Cherokee Technical Forum 14 08-03-2012 12:29 PM
1990 Cherokee no spark Leobram XJ Cherokee Technical Forum 1 08-25-2009 12:24 AM
1990 Jeep Cherokee Sport 2-door harrydunn XJ Cherokee Technical Forum 1 10-25-2007 08:54 AM
1990 Cherokee Sport ... got some questions...:) sweeper2 XJ Cherokee Technical Forum 11 09-12-2006 04:49 PM
1990 Cherokee Sport high rpms? ABZACK XJ Cherokee Technical Forum 4 07-25-2006 10:54 AM

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