Jeep Cherokee Forum

Go Back   Jeep Cherokee Forum > Technical Discussion > OEM Cherokee Tech
Register Forgot Password?
Register Photos FAQ Members List Social Groups Search Today's Posts Mark Forums Read GarageVendor DirectoryvBLive
Search

Welcome to Cherokee Forum!
Welcome to Cherokee Forum,

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!


Reply
 
 
 
submit to reddit
 
Thread Tools Search this Thread Display Modes
Old 08-06-2009, 03:39 PM   #1
Newbie
 
Join Date: Jun 2009
Posts: 5

View 1985xjlaredo's Photo Album My Photos
Cherokee
Default What would cause the injectors not to open?

I have an 88 XJ Chief. 4.0 5 speed. The other night coming home it started to lose power and surge and miss I made it too the drive way then shut it off. How it will not start. I have spark it is blue and strong. I can start it on starting fluid, and I dont smell fuel in the cylinders while Im cranking. The plugs dont get wet either. I don't think that all six of the injectors could have gone bad at the same time. So what sensor could be bad that wouldn't tell the ECM to fire the injectors?
1985xjlaredo is offline   Reply With Quote
Old 08-06-2009, 03:49 PM   #2
CF Veteran
 
Abovetimberline's Avatar
 
Join Date: Jul 2009
Location: Chico,ca
Posts: 2,158

View Abovetimberline's Photo Album My Photos
89 Cherokee
Default

Is the fuel pump working?do you have fuel at the rail? What causes injectors not to open is the cps,but you have spark so it would be the pcm.
Abovetimberline is offline   Reply With Quote
Old 08-06-2009, 04:41 PM   #3
Junior Member
 
Join Date: Aug 2009
Posts: 45

View jeepjeep90's Photo Album My Photos
1990 Cherokee
Default

i have been having the same issue with my renix 4.0 and alot of people have give sooo much help so i will pass it along check to see if you have pressure at the rail when the key is in the on position but not running if you dont check to see if the fuel pump turns on and for how long normal is around 4 seconds change your fuel filter there is two on on the pump one by the passeger frame rail by the tank check vacuum to your FPR
jeepjeep90 is offline   Reply With Quote
Old 08-09-2009, 09:23 AM   #4
Newbie
 
Join Date: Jun 2009
Posts: 5

View 1985xjlaredo's Photo Album My Photos
Cherokee
Default

ok good pressure at the rail with the key on. I can hear the pump turn on when I turn the key. I have good vacuum at the regulator. You said that the "cps" would cause the injectors not to open. Are you talking about the camshaft position sensor in the distributor?
1985xjlaredo is offline   Reply With Quote
Old 08-09-2009, 09:44 AM   #5
Senior Member
 
jd4x426's Avatar
 
Join Date: Jan 2009
Posts: 920

View jd4x426's Photo Album My Photos
1996 Cherokee
Default

the cps is the crank position sensor its on the bellhousing and this is a very common problem with these xjs do a search and you will find hundreds of threads on it first try disconnectiong and cleaning the terminals
__________________
BUILD EM DONT BUY EM
jd4x426 is offline   Reply With Quote
Old 08-09-2009, 11:38 AM   #6
The CF Moderator

 
XJ Stryker's Avatar
 
Join Date: Apr 2008
Location: Smiths Station, Al
Posts: 7,610

View XJ Stryker's Photo Album My Photos
87 Wagoneer
Send a message via Yahoo to XJ Stryker
Default

Quote:
Originally Posted by jeepjeep90 View Post
i have been having the same issue with my renix 4.0 and alot of people have give sooo much help so i will pass it along check to see if you have pressure at the rail when the key is in the on position but not running if you dont check to see if the fuel pump turns on and for how long normal is around 4 seconds change your fuel filter there is two on on the pump one by the passeger frame rail by the tank check vacuum to your FPR

OMG use Punctuation dude.
__________________
1987 Tan Jeep Wagoneer 4.0L 242 4.5 RC on turdy tree's
2006 F-150 King Ranch 5.4L V-8 Triton

Check out my Waggy build here!

XJ Stryker is offline   Reply With Quote
Old 08-09-2009, 01:08 PM   #7
Newbie
 
Join Date: Jun 2009
Posts: 5

View 1985xjlaredo's Photo Album My Photos
Cherokee
Default

I thought that the crank sensor controlled spark? I have had one go out before and I had no spark.
1985xjlaredo is offline   Reply With Quote
Old 08-10-2009, 12:21 AM   #8
Junior Member
 
Join Date: Aug 2009
Posts: 45

View jeepjeep90's Photo Album My Photos
1990 Cherokee
Default

WOW, i didn't realize punctuation was a rule in a forum. I'm here trying to help and your going to pick on me because i didn't use punctuation. Really?
jeepjeep90 is offline   Reply With Quote
Old 08-10-2009, 12:25 PM   #9
Newbie
 
Join Date: Jun 2009
Posts: 5

View 1985xjlaredo's Photo Album My Photos
Cherokee
Default

So would the camshaft position sensor going out cause the injectors to not fire? And when the crank sensor goes out you have no spark, right?
1985xjlaredo is offline   Reply With Quote
Old 08-11-2009, 01:52 PM   #10
Newbie
 
Join Date: Jun 2009
Posts: 5

View 1985xjlaredo's Photo Album My Photos
Cherokee
Default

Anyone?
1985xjlaredo is offline   Reply With Quote
Old 08-11-2009, 02:00 PM   #11
CF Veteran
 
JeepCoMJ's Avatar
 
Join Date: Nov 2008
Posts: 1,999

View JeepCoMJ's Photo Album My Photos
1987 Cherokee
Send a message via AIM to JeepCoMJ
Default

if it's injectors won't open...then your jeep isn't aroused enough to fire it's cylinders.
JeepCoMJ is offline   Reply With Quote
Old 06-20-2012, 12:40 PM   #12
Junior Member
 
jeepsterokc's Avatar
 
Join Date: Dec 2011
Location: oklahoma city,OK
Posts: 68

View jeepsterokc's Photo Album My Photos
1987 Cherokee
Default

i had the same issue on my 87 cherokee. and i tried the cps and replacing the pump and filter. ended up needing a new computer. apparently the computer tells the injectors when to open. but i messed with some terminal wires earlier because they were loose. and i think i friend my computer because theyre not firing again now
jeepsterokc is offline   Reply With Quote
Old 06-20-2012, 12:42 PM   #13
Junior Member
 
jeepsterokc's Avatar
 
Join Date: Dec 2011
Location: oklahoma city,OK
Posts: 68

View jeepsterokc's Photo Album My Photos
1987 Cherokee
Default

im telling you dude. go to a junk yard. and get another computer. mine sits right under the lowest part of my dash on the drivers side far right. a giant grey box with two plugs. or if you have a buddy with another jeep the around the same year. swap em out. i guarentee thats your issue
jeepsterokc is offline   Reply With Quote
Old 06-20-2012, 01:09 PM   #14
Member
 
944.0's Avatar
 
Join Date: Jan 2012
Location: Camdenton, Mo
Posts: 230

View 944.0's Photo Album My Photos
94 Cherokee
Default

Do you people not look at dates?
944.0 is offline   Reply With Quote
Old 06-20-2012, 01:09 PM
 
 
 
submit to reddit
Reply

Tags
fuel, injector, renix
Go Back   Jeep Cherokee Forum > Technical Discussion > OEM Cherokee Tech



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not 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 Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
injectors? claygrassmann OEM Cherokee Tech 5 07-28-2009 09:20 PM
Need 2 injectors for 87 4.0 RCB Wanted 2 07-02-2009 09:12 PM
testing injectors stutter1 OEM Cherokee Tech 0 06-08-2009 10:57 PM
Injectors! Oh boy! syncview OEM Cherokee Tech 17 05-29-2009 03:12 AM
New Fuel Injectors Burns OEM Cherokee Tech 1 12-09-2008 03:50 PM


All times are GMT -5. The time now is 08:34 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.5.2
This site is in no way affiliated with Jeep or Chrysler.

Emails Backup