Starting Issue -
LinkBack Thread Tools
post #1 of 4 Old 07-23-2019, 04:39 AM Thread Starter
Registered User
danwoz's Avatar
1997 ZJ 
Join Date: Jan 2012
Location: Brisbane
Posts: 8
Starting Issue


I have what to me seems to be a really strange problem that I am unable to find similar diagnosis anywhere, even Jeep experts have had a look at it, and everyone has drawn a blank

I am wondering if this could be related to the BCM, does anyone know where this is located on a right hand drive Jeep? Security System, and location of the module?

96 Jeep Grand Cherokee.

So the problem is this. I had an over charging issue which was fixed with new alternator and now the problem with the starting got worse and worse over time, and now I don't believe it is even possible to start it. If I unlocked the car and tried to turn the key it would light all the cluster except the check engine light, every time this occurred I knew the car would not fire, so turning the key off one click locking and unlocking the car and trying again the check engine light would come on then go out and the car would start fine, once the car was normal running temp for a while it would always unlock and start up first time as it should do, if the car was off for a longer period of time then the original problem would happen.

This issue got worse and worse where it would require attempts of unlocking turning key, no check engine, turn key back one turn, lock and unlock, turn key to point just before turning to start. I would have to do this mentioned process over and over again until the check engine light came on and went out again. Even with the issues as I explained here at times 30 times doing this in the final days before I took the car in, once the car was up to full running temp it would always unlock and start first time.

Most frustrating thing is that there is no codes to read.

So the diagnosis shows that when the check engine light does not come on there is also no power at the ASD relay (tested and listening for relay when unplugging and plugging back in), which then nothing at the injectors or coil.

With the car running I have been quite rough with all the loom cables into the PCM and main engine relay box hoping the car would stall but never had an issue with that.

Checked all the fuses, cleaned the contacts and applied a little electrical paste all the ones related to ignition and running of the vehicle
PCM has been replaced as well as a module behind where the key is inserted in the steering column from another running car that I had.

The problem here typically is the opposite to other reported issues that I have been able to find, where the car starts no problem then stops when it gets hot, or just wont start, typically was a short, loose wire, one youtube diagnosis one I saw was wires shorting on the header pipes to the oxygen sensor. All of which don't really fit with the issue I describe.

I have two new oxygen sensors in the car, should I try the old ones back in or is it like to be unrelated?

Has anyone had the same issue and resolved it please???

danwoz is offline  
Sponsored Links
post #2 of 4 Old 07-23-2019, 10:15 AM
Registered User
jtec's Avatar
2014 JK Wrangler 
Join Date: Oct 2017
Posts: 6,796
cycling the ign switch on off gives different results (CEL/ASD) - maybe take a look at the ing switch, not the lock the electric portion. Not uncommon to have contact issues esp after years.

Can you utilize a wiring diagram, use a test light and a DVOM? We likely could post a diagram for you.

When I see the price of OEM I think aftermarket.
When I see the quality of aftermarket I think OEM.
jtec is offline  
post #3 of 4 Old 07-23-2019, 10:00 PM
Registered User
1997 ZJ 
Join Date: Nov 2014
Posts: 606
Yeah, I think I read on here that the electrical contacts in the ignition switch are one of the common problem with zj's. I don't have a thread saved for it, but you can do a search in the box at the top.
RedRiverT is offline  
post #4 of 4 Old 07-24-2019, 03:11 PM Thread Starter
Registered User
danwoz's Avatar
1997 ZJ 
Join Date: Jan 2012
Location: Brisbane
Posts: 8
Thanks everyone, I will take a close look at that. It will make me crazy if it finally works out to be that simple, but it will be great if that is the problem!!!
danwoz 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:


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

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