Jeep Cherokee Forum

Go Back   Jeep Cherokee Forum > Technical Discussion > OEM Cherokee Tech
Sign in using an external account
Register Forgot Password?

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!

injector pulse problem

submit to reddit
Thread Tools Search this Thread Display Modes
Old 12-12-2010, 04:53 AM   #1
Join Date: Dec 2010
Posts: 2

View jbaghni's Photo Album My Photos
Default injector pulse problem

any body please advise possible cause of the following problem:
from time to time it happens that my jeep cherokee 1990 4.o l have no injector pulse , spark is ok , fuel pump is ok , but when i unplug and replug these four relays near the battery ( latch and fuel pump and oxygen heater relays ) the injector pulse is ok and the car starts .is it a problem of bad ground ?
please if any body faced similar problem give an advise.

jbaghni is offline   Reply With Quote
Old 12-12-2010, 06:23 AM   #2
CF Veteran
freegdr's Avatar
Join Date: Mar 2010
Location: Happyville...
Posts: 32,403

View freegdr's Photo Album My Photos
1989 xj sport 2dr Cherokee

Have you tried changing the relays yet maybe one is bad
Its all in your altitude,horn broke watch for finger
When asking for help here and not listening to test procedures, why ask?
freegdr is offline   Reply With Quote
Old 12-12-2010, 09:08 AM   #3
CJ7365's Avatar
Join Date: Nov 2010
Posts: 187

View CJ7365's Photo Album My Photos
1994 Cherokee

I had a similar issue, and finally loacted the problem by accident, the main injector pulse wire going to the injectors had broken, the break was located where the main harness running from the injectors going back to the firewall then bending up and back over to the main fusebox (autoshut down relay) while performing a volt check of the injectors I had moved the wiring harness and I got good voltage, after undoing all the heat shrink I found the break. I respliced the main wire, and I was G2G
CJ7365 is offline   Reply With Quote
Old 12-13-2010, 12:20 AM   #4
Join Date: Dec 2010
Posts: 2

View jbaghni's Photo Album My Photos

Hi Messrs Freegdr , CJ7365
Thanks for your advices , and at the weekend i will do what you suggested .

Thanks and best regards
jbaghni is offline   Reply With Quote
Old 12-13-2010, 05:57 AM   #5
CF Veteran
Join Date: Nov 2010
Location: In the middle of Minnesota!
Posts: 4,839

View tjwalker's Photo Album My Photos
1999 Cherokee

Grounds can be the root cause of many electrical gremlins. (especially on RENIX vintage which is 87-90) Refreshing grounds is NEVER a bad idea!

You can't just check or look at these grounds. You must remove, scrape, clean until shiny the cable/wire ends and whatever they bolt to. The one on the back corner of the head, and where it attaches to the firewall. Scrape the paint from the firewall. Best to replace that woven cable with a #4 or #2 gauge cable. You can attach the one end to the intake manifold if you would like.

Next go over to the engine dipstick tube stud. Remove the nut and clean the wire ends and scrape the block until shiny at the stud. Reattach tightly.

If you are so inclined, add at least a #6 cable from the negative terminal of your battery to one of the bolts on your radiator support. Scrape the paint off first.
Without data, all you have is an OPINION!

Past Jeeps: '49 ******, '81 Scrambler, '88 Comanche

Current Jeep: 1999 XJ Sport, bone stock, daily driver.

I work on Jeeps!!
tjwalker is offline   Reply With Quote
Old 12-13-2010, 05:57 AM
submit to reddit

Similar Threads
Thread Thread Starter Forum Replies Last Post
No Spark, No Fuel, No Injector Pulse Nukasu OEM Cherokee Tech 34 01-01-2011 03:55 PM
No injector pulse CJ7365 OEM Cherokee Tech 24 11-19-2010 08:20 PM
injector pulse problem bradaustin OEM Cherokee Tech 4 09-07-2010 04:30 PM
no injector pulse slimer OEM Cherokee Tech 3 08-20-2009 07:12 PM
No spark and no injector pulse sinic Grand Cherokee Tech 10 12-09-2008 02:40 PM

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

All times are GMT -5. The time now is 09:16 PM.

This site is in no way affiliated with Jeep or Chrysler.

Emails Backup