Noah911

To start: You will get plugs and wires. I recommend using dielectric grease at both ends of the plug wires, and your distributor wire.
Grab your wires.
Fill the boots of each wire with a bit of the grease.
When you pull off the old wires. Do them one at a time to keep them in their correct order. It is important. The wires can be routed different ways after hooked-up in the correct order. I took a picture of how I think is the best way to route the spark plug wires at the end of this opening post. Remove the plugs CAREFULLY by hand after you break-through their grip just a little bit counterclockwise. Then only by hand.. to remove and tighten the new plugs back down.. to finger tight.. go approximately 1/8 - not quite one-fourth clockwise turn with the ratchet to make your final snug fit.
On the ZJ, this forward most plug presents problems, both removing and snugging in the new spark plug.. (it is tight and difficult..) Especially, if you have limited dexterity and/or strength in your hand(s), or just too big of hands too. For when you are removing it, the valve cover lip is in the way of the spark plug socket. It prevents you from going straight at it.. I needed a joint-nuckle extension attached to my longer extension bar - to the ratchet, to get it removed.
This is a picture of the best routes for the spark plug wires, and for the new distributor wire to go.. Mine whoever did this stuff before had them all ****-eyed and miss-routed in there, so I made them go like this way shown. It seems to keep most of the stress away from the boots and bends etc this way...
Anyone know if I am supposed to have any type of hose or something hooked up to my airbox in the lower center of this picture above?
The old wires service life has ended.
Any plug reading experts have an opinion of these, and their condition. Looks like this was over-due. See the last one with litterally zero gap. Others with way too much gap. Some strange markings etc... How do you think these ones look? I'll pull the new ones here after awhile to inspect them after it is all tuned-up proper.
Pulling out the big gun here for the grounds and electrical connections cleaning with a wire wheel. I tell you.. If you ever go to drilling solid steel to make holes for bolts like I did for my towbar brackets.. Go SLOW slow slow. Steady slow RPMs, and every minute or less dab a finger-full of engine oil to the spot where you are drilling, to keep it cool. No NO no high-speed tourque and metal with high RPMs are one of those things that never ever go together, unless you are using a sophisticated machine, or else you wouldn't mind crippling your dominant grip-holding hand on the drill when it grabs, it could easily break all of your palm-finger metatarsal bones in your hand that way!
A beer afterwards maybe?

dave1123

That fitting you're talking about is where my IAT sensor is located. OH...Wait! you're talking about the filter housing. That hose is supposed to be connected to the front crankcase vent on the valve cover. The fourth plug in your photo shows signs of some compression leakage on the gasket. What happened to the missing one? Did you break it? LOL! Funny how the one with zero gap shows it's been firing. Not well, but firing. I always check the gap on new plugs before I install them. I'll bet that one was mishandled in shipment and never checked. I use NGK plugs on waste spark engines and notice they come with cardboard tubes around the electrodes just for that reason.

On the drilling. Yes, go slow on the rpms and keep it cool. Just as you think you're about to break thru, let up on the pressure a lot! Be VERY careful enlarging an existing hole, especially in sheet metal. Grabbing is guaranteed! Whenever possible use a drill press because you can control the feed a lot easier.

Thanks for the post, Noah. You seem to have an intelligent head on your shoulders.

Noah911

The sixth plug is still laying on the grass outside where I tossed it the night prior..

What do you think of the fourth. I see the differences, and the zero gap looks pretty darn good considering. I'll definitely see what the new ones change to look like over the next little bit of time soon... You think the compression leak looking cylinder is a big deal? Could it be a ring? Something that hopefully developes no large overall decreased performance, or problems? I should do further investigation huh? Look at the numbers doing a compression test next sounds like the appropriate next step doesn't it?

Noah911

I have no IAT sensor? I'll have to look into this. It could have been relocated? I am going to see what the WJs looks like at the airbox too, to compare now. Look up a diagram of the ZJ...

dave1123

No, I'm saying the compression leakage was from not being tightened enough. I've edited my post since you read it. That hose is supposed to be connected to the front crankcase vent in the valve cover so it draws in filtered air.

IDK about ZJs and their IAT. It could have been relocated by the PO. Some guys move it to the intake piping somewhere because they think it will show cooler air and result in better mileage. If anything, it will enrichen the mixture.

Noah911

Gotcha, I see what you mean for the 4th plug. I will just re-check them all later then. I appreciate the opinion. I'll throw the new spark plug readings at you again when the time comes for that.

dave1123

Look at live data on your scanner and see what your intake air temp is. I remember my WJ showed 158* IAT when the ambient air was 72*.

Noah911

I will.. That would be a good thing for me to do just to see now.

Noah911

Hey Dave. What do you think.. Remember me asking above if I should have something connected to this spot on my airbox? I zoomed it out retaking the picture, to show more. It looks like my forward crankcase breather hose line is hooked up, and pulling in fresh air from my airbox already somewhere else right?

I still do not know if this is normal or not? It looks like it should have something connected up to it here.. at the airbox?

There are no running issues with the Jeep. There never has been since I got it. Maybe at most around 1,200 miles so far.

dave1123

No, that's okay where it's hooked up now. That airbox cover may have been molded to fit other models as well. I'm thinking that fitting should be plugged because it's after the filter and may be drawing in unfiltered air. I see your IAT is in the manifold second to the last position toward the firewall. It's in the forward runner on my WJ. Why? You'd have to ask Chrysler. Maybe to keep it away from the CCV inlet?

Noah911

You read my mind. I was wondering why is there a tube coming off into my airbox possibly drawing unfiltered air up into my intake? It looked un-correct to me, and like it needed to be corrected. I'm going to block it off.

My missing IAT sensor is un-missing now.