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-   -   Distributorless 4.0L Tuneup (http://www.wranglerforum.com/f282/distributorless-4-0l-tuneup-140021.html)

redneckpilot 02-15-2012 10:25 PM

Distributorless 4.0L Tuneup
 
I started tonight knowing that if I just posted a question about the tuneup for my 06 TJ 4.0L without doing research I'd be told "use the search function". So I did. Still have questions though.
  • So I get that I don't have a distributor - Awesome
  • I found out that I want dual tipped platinum plugs, Autolite APP985 was what I think Jerry recommended on a previous page.

But my question is how often do I have to replace the rail/coil packs that provide spark to the plug?

I'm about to hit 50k on my baby, and its starting to do that I-don't-care-I-want-a-tuneup-or-I-will-randomly-kill-starting-out-from-the-stop-sign dance that only a cold engine in dire need of a tuneup does. I don't like that dance, it makes me angry. So this weekend is going to be tuneup time.

Also, is there anything else that I should know about doing a tuneup on an '06 TJ that would differ from my chevy pickups I've done in the past? Any gotchas?

Thanks for the help!

UnlimitedLJ04 02-15-2012 10:31 PM

coil packs are replaced when they go bad. they don't go bad very often.

change all your fluid too...tranny, engine, power steering, brake fluid, diffs, t-case...grease the ball joints, steering, u-joints in the driveshafts (may require removing driveshaft)...etc.

MechanicJay 02-16-2012 11:28 AM

Quote:

Originally Posted by UnlimitedLJ04 (Post 2036735)
coil packs are replaced when they go bad. they don't go bad very often.

+1

Mine just went bad, the symptoms:

Ignition breakup at high rpm (3500+)
Arcing sound coming from the rear most coil pack -- internal arc, could only hear it with the hood up.
Random misfires when cold.
High-load, low RPM hesitation (such as from a stoplight).

No codes thrown.

It runs 100% better with the new coil rail.

Rpkittle 02-16-2012 12:01 PM

If it doesnt have a distributor, what does it have? and how does it function differently?

Sccafire 02-16-2012 12:16 PM

Basically, it is all done by the pcm and several sensors.

DuruConsigliere 02-16-2012 12:24 PM

Just a added note. When you do your tune up you may want to clean up the Throttle Body. Just a thought.

redneckpilot 02-16-2012 05:08 PM

Thought the '06 was fuel injected, if there's a throttle body on it, I may wanna go get my glasses re-checked, because I haven't seen one yet. It is about that time for my yearly check anyway :banghead:

UnlimitedLJ04 02-16-2012 05:12 PM

Quote:

Originally Posted by Rpkittle (Post 2038301)
If it doesnt have a distributor, what does it have? and how does it function differently?

The new 4.0L's all have coil packs. Three coils packs on the rail if I remember correctly. Cam position and timing is handled by the cam position sensor and the PCM.

Quote:

Originally Posted by redneckpilot (Post 2039274)
Thought the '06 was fuel injected, if there's a throttle body on it, I may wanna go get my glasses re-checked, because I haven't seen one yet. It is about that time for my yearly check anyway :banghead:

All the TJ's are multi-point fuel injected, and do have throttle bodies. The 05-06 use a different throttle body than 97-04.

cntryboy232 02-16-2012 08:07 PM

im about to hit 100000 on mine and going to flush the whole system. Other than that and spark plugs i dont know what else to do.

tangofox007 02-16-2012 08:35 PM

Quote:

Originally Posted by redneckpilot (Post 2039274)
Thought the '06 was fuel injected, if there's a throttle body on it, I may wanna go get my glasses re-checked, because I haven't seen one yet.

What did you see? Or have you not raised the hood yet?

redneckpilot 02-17-2012 11:41 AM

I've raised the hood, and been under her several times. Apparently I need those glasses checked, because I guess I was looking for something different, more like what my Silverado had. Didn't mean to come off sounding like a smartass. :facepalm: Live and learn.

On a separate note, somebody gave me good advice once to clean out the throttle body when I do a tuneup - I think I'll take them up on that.

redneckpilot 02-17-2012 11:54 AM

Also, I thought that throttle bodies were something specific to single point injection systems. Learning more every day.

UnlimitedLJ04 02-17-2012 12:47 PM

Quote:

Originally Posted by redneckpilot (Post 2041871)
Also, I thought that throttle bodies were something specific to single point injection systems. Learning more every day.

all the throttle body does is meter the air that the engine gets. basically the same thing the throttle blades on a carb do. so if your silverado was a gas motor which wasn't carb'ed, it had a throttle body. some diesels even have throttle bodies now...

if fuel injected, where & how the fuel is injected determines whether its SFI, MPFI, TBFI, etc. In the case of the Jeep 4.0L, it's MPFI, so each cylinder has it's own fuel injector, and fuel is injected into the intake manifold adjacent to the combustion chamber.

LJDan 02-17-2012 01:36 PM

On the distributor topic...look up opda on here and jf and learn the procedure to pull and inspect. It is known to us 05 and 06 guys as the oil pump drive assembly that is located on the passenger side of the motor right where you would expect to see a distributor. They are poorly designed and improperly lubricated and have been known to fail and cause major damage if you don't keep on top of them. If your jeep is an 06, check it immediately b/c that could be what is causing your problem.


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