How to reindex the camshaft position sensor - JeepForum.com
Reply
 
LinkBack Thread Tools
post #1 of 56 Old 12-25-2010, 09:00 PM Thread Starter
Kevin108
Registered User
2000 XJ Cherokee 
 
Join Date: Aug 2009
Location: Portsmouth
Posts: 3,951
How to reindex the camshaft position sensor

From what I've read, the timing chain stretches out as you rack up the miles on your Cherokee with a coil rail and at some point it gets outside of the range the computer can correct for it. Mine got there right after I installed a new crank position sensor and hit 130,000 miles.

The process is easy. You need a helper, a toothpick or small drill bit, some basic hand tools and a "mirror on a stick" so you can see the timing marks on the bottom of the cover.

Remove the coil rail, the first spark plug and the camshaft position sensor.
Carefully place a finger of the spark plug hole.
Have your helper bump the starter a little at a time until you feel pressure.
Break out your mirror and check your timing marks.
Use a ratchet or wrench, 19mm I think, to turn the crank forwards to the zero mark.
Remove the camshaft position sensor from the camshaft synchronizer.
Loosen the retaining fork that holds in the camshaft synchronizer.
Find the small hole in the outside of the housing for the oil pump drive shaft.
Find the small hole on the magnet inside that indicates camshaft position.
Carefully turn the housing on the camshaft synchronizer until you can align those two holes and insert a toothpick or drill bit straight through them.
Tighten down the retaining fork, reinstall the camshaft position sensor, spark plug and coil rail.
Enjoy quicker starts and having avoided the problems that this stupid sensor causes when it gets even further out of spec.

The NAXJA guys finally found my problem and provided me this link to learn what the fix was. The process for finding top dead center and zeroing the timing came from my dad although I performed the work myself. It's basically the modern iteration of setting the timing on something you're led to believe you don't have to set the timing on.

Also, this is just the shade tree mechanic version of the fix. Alternately you can take it to a shop with a DRB scan tool and they can reprogram the computer to compensate the difference without ever having to open the hood or turn a wrench. A JF member in a thread I don't recall posted that the shop he went to wanted over $100 to do this. A guy in my Jeep club said he'd do it for free for me. Like anything else, YMMV.

(This may still be edited for terminology and additional accuracy.)

To illustrate the location



My build thread has pics again. http://www.jeepforum.com/forum/f177/kevin108s-2000-xj-build-867428/
Kevin108 is offline  
Sponsored Links
Advertisement
 
post #2 of 56 Old 12-26-2010, 07:16 AM
mcthnif
Registered User
2001 XJ Cherokee 
 
Join Date: Apr 2008
Location: Clarksville IN
Posts: 204
Great post. I have done this before, but You have done a great job laying out the procedure. It should be made a sticky.
mcthnif is offline  
post #3 of 56 Old 01-22-2011, 01:30 PM
sbxj
Registered User
 
sbxj's Avatar
2001 XJ Cherokee 
 
Join Date: May 2003
Location: Oz
Posts: 1,029
are you kidding?
I think i'd rather pay a professional to do it right than lowball it.

'01 XJ 2DR Sport
GoJeep/Howto/BiXenonProjectors/XJ

'99 WJ Laredo, 4.0L with HID Retrofit
WJ HID Retrofit Pics
sbxj is offline  
post #4 of 56 Old 01-22-2011, 09:23 PM Thread Starter
Kevin108
Registered User
2000 XJ Cherokee 
 
Join Date: Aug 2009
Location: Portsmouth
Posts: 3,951
The DRB will reprogram your computer to compensate for the stretched timing chain without actually fixing the condition causing the problem. The instructions about allow you to physically adjust the CPS for the condition. The DRB might be good for fine tuning but short of replacing a timing chain simply because it stretched some, this is indeed a proper repair. Also I am not 100% certain, but I believe if you perform a factory reset on the computer, you will loose any aftermarket DRB reprogramming.

How do you think a "professional repair" would be different?

My build thread has pics again. http://www.jeepforum.com/forum/f177/kevin108s-2000-xj-build-867428/
Kevin108 is offline  
post #5 of 56 Old 01-29-2011, 09:13 PM
Paraleyes
Registered User
2000 XJ Cherokee 
 
Join Date: Mar 2009
Location: Spokane, WA
Posts: 904
I agree... STICKY! It might be a good idea to list the symptoms you had before you made the fix.
Paraleyes is offline  
post #6 of 56 Old 01-30-2011, 07:17 AM Thread Starter
Kevin108
Registered User
2000 XJ Cherokee 
 
Join Date: Aug 2009
Location: Portsmouth
Posts: 3,951
When I get a chance I would like to add the codes and symptoms I was having along with more pics and the verified socket sizes for everything.

My build thread has pics again. http://www.jeepforum.com/forum/f177/kevin108s-2000-xj-build-867428/
Kevin108 is offline  
post #7 of 56 Old 01-30-2011, 08:41 AM
ChEaPsK87
Registered User
1987 XJ Cherokee 
 
Join Date: Jul 2010
Location: Concord NC
Posts: 602
Quote:
Originally Posted by sbxj View Post
are you kidding?
I think i'd rather pay a professional to do it right than lowball it.
what did he not do that a pro would? nothing but save $ so hate somewhere else please...thank you

great write up! i agree with everyone STICKY
ChEaPsK87 is offline  
post #8 of 56 Old 01-30-2011, 10:22 AM
Paraleyes
Registered User
2000 XJ Cherokee 
 
Join Date: Mar 2009
Location: Spokane, WA
Posts: 904
Nah, I do think this is an important bit of information. I see countless threads of 00-01 XJs having these symptoms. I'm sure there are many other Wranglers having this same problem too. I'll be sure to post back after I do it and let you know my results.
Paraleyes is offline  
post #9 of 56 Old 01-30-2011, 11:19 AM
robsjeepxj
Registered User
2000 XJ Cherokee 
 
Join Date: Sep 2007
Posts: 1,644
Quote:
Originally Posted by sbxj View Post
are you kidding?
I think i'd rather pay a professional to do it right than lowball it.
Go pay then, don't want you to get your pretty little nails dirty now. Maybe your missing the point of a "technical forum" about jeeps. Hint: It's so people can share there problems and find solutions so they don't have to pay someone $100 to fix something they can fix for FREE themselves, get it now? Geez if you don't like it SO WHAT it works and lots of people have done it, including myself, so well.... that's about all I have to say about that.
robsjeepxj is offline  
post #10 of 56 Old 01-30-2011, 04:49 PM
Paraleyes
Registered User
2000 XJ Cherokee 
 
Join Date: Mar 2009
Location: Spokane, WA
Posts: 904
Where in the world are the timing marks? Found the tab under the cover, but nothing on the balancer? Where?
Paraleyes is offline  
post #11 of 56 Old 01-30-2011, 05:01 PM
robsjeepxj
Registered User
2000 XJ Cherokee 
 
Join Date: Sep 2007
Posts: 1,644
Quote:
Originally Posted by Paraleyes View Post
Where in the world are the timing marks? Found the tab under the cover, but nothing on the balancer? Where?
There should be a small tab on the drivers side of the timing cover with numbers/grooves on it, the balancer just has a line on it to match them up with.
robsjeepxj is offline  
post #12 of 56 Old 01-30-2011, 07:18 PM Thread Starter
Kevin108
Registered User
2000 XJ Cherokee 
 
Join Date: Aug 2009
Location: Portsmouth
Posts: 3,951
If it was daylight, you probably could have seen the timing marks in the mirror in this pic. Mine are a little greasy. Yours probably are as well. This is the area you need to look for them in.


My build thread has pics again. http://www.jeepforum.com/forum/f177/kevin108s-2000-xj-build-867428/
Kevin108 is offline  
post #13 of 56 Old 01-30-2011, 10:49 PM
Paraleyes
Registered User
2000 XJ Cherokee 
 
Join Date: Mar 2009
Location: Spokane, WA
Posts: 904
Uggh... see my problem is I'm in a wheelchair. I can do just about anything I can reach underneath or outside the rig, but not that. I think my helper may have been looking for it at the back of the pulley. I couldn't see it at all. Looks like the balancer is actually right there with the mirror resting on it.
Paraleyes is offline  
post #14 of 56 Old 01-30-2011, 11:07 PM
justanotherjpr
Registered User
 
Join Date: Nov 2007
Posts: 6,336
Thanks for posting this. I get the feeling it wont be long until I'm adjusting both mine and Paraleyes' cam sensors.

Quote:
Originally Posted by Motorcharge View Post
So do you actually hear your thoughts in your head or is it just sort of a dull roar before you smash your face into your keyboard and just submit whatever dumb **** ended up on the page?
justanotherjpr is offline  
post #15 of 56 Old 01-30-2011, 11:33 PM
ratmonkey
R.I.P.
 
ratmonkey's Avatar
1997 ZJ 
 
Join Date: Dec 2006
Posts: 19,793
NEVER turn a motor backwards. Especially when you're trying to adjust for timing chain slack.



The dealer doesn't program your computer for the fuel synch, they use the tool to monitor the dwell while turning the oil pump drive/cam sensor assembly into the correct window.


The cam sensor has nothing at all to do with what is traditionally called timing, which is spark advance. Spark advance is read from the crank sensor only.

Anyway, if you have chain stretch the proper solution is to spend 75$ on the chain and gasket set and fix it properly.

'97 zj 5.2, some stuff, some other suff, and some things that even work sometimes.

ratmonkey is offline  
Reply

Quick Reply
Message:
Options

Register Now



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

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

Password:


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



Email Address:
OR

Log-in









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
Camshaft position sensor??????? yjasoldasiam XJ Cherokee Technical Forum 2 07-05-2010 02:38 PM
Camshaft position sensor ajeepthing XJ Cherokee Technical Forum 0 09-29-2009 06:16 PM
CAMshaft position sensor BlkBird XJ Cherokee Technical Forum 4 07-21-2007 09:37 AM
halls effect sensor or camshaft position sensor? mackg@goodweb.o XJ Cherokee Technical Forum 4 07-13-2007 06:23 AM
camshaft position sensor???? ThaKingXJ XJ Cherokee Technical Forum 4 03-10-2007 03:21 PM

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