TJ Hesitation

 OK - the sparkplugs have been changed in Ruby now and by the looks of it, it was well overdue. The change out wasn't bad and it's hard to believe that this is called a tune up on the newer 4.0 liter engines. No wires, no distributor cap, only sparkplugs. Here are the pics of what went in and what came out.

Here's what went in! Champion 4412 Double Platinum Truck Plugs.

This is what came out! OMG - possibly the OEM NGK plugs?

Seems to have made quite a difference. My idle is now steady at 700 rpm's, my pickup off the line is better, the engine sounds better as in it seems to run smoother. Now the only thing I'm waiting on is to see is if at highway speeds the so called hesitation (bump, lurch, flat spot, etc.) is gone after running at 60+ mph's after 20-30 minutes. I'm sure I'll find this out on the run up to Payson next Saturday. If it hasn't gone away - I'm heading down to Tucson to camp out in Craig's yard until he can figure out what the issue is. Just kidding Craig.

JD

 JD, great job, those definitely look like your issue.  My bet is that you will be back to normal and purring like a kitten on the highway!  Now you can see why I change my plugs about every 30K-50K, Jeeps tend to be hard on them.  I would still recommend pulling them out and regapping them every year or so.  I can't believe it even  was starting for you with that amount of gap.

Craig

 JD, by the way, if you didn't know, you can tell allot about the health of an engine by the looks of the plugs, unless you cleaned them before the picture, your engines looks to be in pretty good health, there is no oily build up in the base of the threads that protrude into the engine head, and little to no carbon build-up, indicating good valve and piston sealing. 

Craig

Craig,

I did not clean up anything on the old plugs. The only thing I did was after breaking them loose I took an air hose and blew out the area to remove any dirt that may have fallen off so it wouldn't be forced down into the engine when I put in the new plugs. As I said this was before I removed the old plug after initially breaking it loose.

What about the angle of the points. I heard that if your plugs wear at an angle that there could be something wrong. I was also told that they will burn at an angle because the gap is not set correctly. Does this sound right to you?

JD 

 The angle that they are at now is just simply from the material wearing away over time from the spark.  Re-gapping once in a while would have prevented this and extended the plugs life a bit.  But like I said before, plugs are a cheap insurance policy.

Craig

 HOLY CRAP DUDE !!!!!!!!

Not HOLY CRAP - more like DIRTY PLUGS!

JD 

 JD,

How's Ruby running now?  Haven't heard from you since you got the plugs changed.  I figure you are probably running around with a renewed smile on your face.  Or maybe you got the lift installed and are out on shake down runs.  Be sure to check tightness of your hardware about every 500 miles or so, for a couple of months, I constantly was finding hardware loosening up on me.  But it seems to have slowed or stopped.  My biggest issue now is keeping the steering wheel centered, although an easy fix with a turn of the drag link.  Mine seem to hit the tie rod when the diff is stuffed at certain points.  Adjusting the drag link doesn't mess with your alignmnet if you didn't know and you can adjust this with out consequence.  Here is a picture if you are not sure which steering component is which.

Let me know if you have any questions

Craig

 Craig,

Ruby seems to be running fine for now. I have not taken her out on the highway and run her at high speeds for any length of time so I'm not sure if the problem has been fixed. Hopefully I can so that this weekend if time permits. I missed the run to Payson last weekend so I didn't get her out at all to check.

I go in tomorrow to verify that all the components of my lift kit are in and I have the installation date set for this Thursday & Friday. Hopefully I can get it done this week as I've been waiting for going on 4 weeks now for the parts to arrive. Cross your fingers.

What do you mean by keeping your steering wheel centered?

JD

 What I mean by keeping your steering wheel centered, is, once you lift your jeep the angles on your drag link changes and when you are out off-roading you will hit rocks and what-not, and this will cause the drag link to sometimes hit the diff and or just rotate from stress.  Your Jeep will steer straight and won't pull or anything, but your steering wheel will not be staight when the vehicle is going straight.  Not a big deal, except that once it gets to far out of wack, your turn signals won't cancel at the appropriate time.  But like I said, it is an easy adjustment with no alignment needed.  I wouldn't worry about it until it happens, I just thought I would let you know ahead ot time about it.  Sorry to worry you if I did.

Craig

 JD, So tell me what you did to make the Rubi run better.  Was it the plugs, after seeing them, that would be my guess!  Did you end up getting the engine "decarbonized" like the stealer wanted you to do?

Craig