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View Full Version : Setting Timing on 4.0 jeep



XJ4IV
03-27-2011, 08:36 PM
Alright after talking with Justin from WORP I have decided that I might need to A. check my timing and B. adjust my timing...
At this point I DO have a timing light and I do have a jeep that is running
what I DON'T have is knowledge of how to adjust the timing and how to CHECK it properly Ive checked youtube for jeep specific but came up with nothing.
Can anyone show me where the indicators are on the crank pulley and also I need to know how to adjust the timing... I am PRETTY sure its on the distributor but where do I clock it?

msmoorenburg
03-27-2011, 09:18 PM
here is my info i dug up!

http://i7.photobucket.com/albums/y299/msmoorenburg/timing-1.jpg

http://i7.photobucket.com/albums/y299/msmoorenburg/timing1-1.jpg

http://i7.photobucket.com/albums/y299/msmoorenburg/timing2-1.jpg

Adjusting the Dist cap :(

http://i7.photobucket.com/albums/y299/msmoorenburg/timing3.jpg

http://i7.photobucket.com/albums/y299/msmoorenburg/timing4-1.jpg


Hope it helps :thumbsup: If your still lost I'll dig up my light and you can swing by

XJ4IV
03-28-2011, 09:25 AM
I have a light what Im wondering is on the crankshaft pulley shown in the very last pic above is where is the indicator? shouldnt there be some sort of indicator when at idle it sits in that field when looked at through the timing gun...

bigjim350
03-28-2011, 09:41 AM
The only indicator on the crank pulley, will be a small groove on the rear of the pulley. If you look down at your pulley, with the belt on, you can see just a small amount of the metal pulley behind the belt. The groove your looking for will be there.

xj4life2
03-28-2011, 01:23 PM
Uhmmm timming on a 4.0 is computer controlled based on the signal from the cam pos and the crank pos sensor you should not have to adjust it at all. If you do the computer will try to put it back where it thinks it should be.

LizardRunner
03-28-2011, 01:40 PM
I have to agree with Payless on this one. the only time you "set the timing" is when you're replacing the timing chain and sprockets or changing the cam. In those instances you are setting to timing marks on the sprockets. Our wonderful sensors do the rest and any trying to manually set it will just make it AFU.

XJ4IV
03-29-2011, 08:25 PM
ok so what would cause the whole back firing now when I let off throttle... I was talking to worp a few days ago and he said it sounds like a timing issue... so what am I lookin for here? I DID take my light to it today and noticed that it fluctuated at idle but when placed under about 3500 RPMs it holds steady while increasing the RPMs it moves up a little bit, but when I let off the little dot dances around on the dial area... I opened up the distributor to check things out and found nothing out of place but I did clean the surface of the rotor which really wasnt an issue so im lost...

JENSSEN
03-29-2011, 10:46 PM
Check your EGR,...

LizardRunner
03-30-2011, 10:22 AM
could be the CPS or the TPS. When my CPS was going out, two things would happen, it would surge a tad when first warmed up and on occassion while doing 40 at 1000 rpm it would just die, rpms would drop to zero and then suddenly it would start back up from a press of the gas pedal. Replacing the CPS took care of both those problems. Just a few days ago I thought I was starting to have problems with the TPS but checking it all out I found a loose ground wire to the body and tightening that after a good cleaning has stopped the problem.

XJ4IV
03-30-2011, 10:30 AM
where exactly is the EGR on this thing?
I forgot about that DUH it totally makes sense!

ice_cold
04-03-2011, 06:38 PM
Have a CPS issue here, did what is on this site to test it.

http://www.jeepforum.com/forum/f11/98-cherokee-4-0l-no-spark-coil-tests-good-905398/

It was while reading it I found out about back fires and other CPS issues.

Now I have to find and replace the sucker

goofyjeeper
03-30-2013, 02:53 PM
the cps hook up is above your intake manifold back by the firewall, and the sensor is is in the top of your tranny.. not a hard thing too replace.. but what is a tps?? i'm runnin outa things too check, and my buddy says mine has advanced timed, mayb jumped a tooth or somthin...

4.3LXJ
03-30-2013, 03:37 PM
tps is throttle postion sensor.