Changed Plugs Today.

[Powerslave]

Well, I under went the chore of replacing the spark plugs...

All in all, was fine, just had to remove the intake tube...

I used Bosch Platinum +2s, like I did in my Avenger. Runs nice.

This is kind of nice, the Coil-Plugs, because with little modification, you can replace them with individual Blaster coils, and regular plug wires, with long boots. I dread the cost of a factory replacements, so, hooking up a modified system won't be hard, from what I see. There is plenty room to mount six coils, or thee dual coil setups. The signal and supply wires only need routed to the coil packs... Replacing just ONE if ONE goes bad? Just have to make sure the individual coil delivers the same spark power as the factory plug-coil. Need specs on that, anyone know the spark voltage?

 

[twack]

Why the stock setup is more then fine, and since your adding no power and having no problem with spark blow out why would you need an upgrade

 

[Powerslave]

No need for an upgrade NOW, but, when you use the +2 and + for bosch plugs, the spark voltage us the same, but now is divided by two arcs or four. The more arcs, the thinner each individual ark is, while still delivering the overall voltage. With the +2s, it should be ok, but if I was going to the +4, I would upgrade, if I felt like it.

If you want a full spark brightness, or PUSH, on both anodes, or all FOUR, you should upgrade the coil packs to deliver a higher voltage, to make the two or all four arcs as good as the single arc on a regular plug.

Voltage is PUSH, where AMPS is current. There are no dangerous AMPS in the spark plug voltage, it's all PUSH; Voltage. The more push you have, the brighter and thicker the arc. Taking the normal voltage, and splitting it by 2 or 4 has some effect on the density of the spark, unless the plug has a lower resistance than the single anode plugs.

The idle is smoother now, but a fresh set of plugs could do that... With more arcs, the fuel is burned better.

I also changed my Transfer case fluid today... I got about two quarts in it...

 

[Awww KJ]

No need for an upgrade NOW, but, when you use the +2 and + for bosch plugs, the spark voltage us the same, but now is divided by two arcs or four. The more arcs, the thinner each individual ark is, while still delivering the overall voltage.

Electricity still takes the shortest path to ground; it does not divide itself as you indicate. Those plugs are just a profit margin item.

 

[Marlon_JB2]

I'm really, really confused by your post, Powerslave. Maybe it's just me?

Is $40 or so a "cost" to really dread for a replacement coil pack at the dealer? Oh, and wholesalemopar.com has them for under $30?

And the advantage of coil-on-plug is only having to replace what's needed. If the coil for cylinder #6 goes out, that's all you need to replace is that coil and no other.

 

[Powerslave]

I know it does not divide "by itself" the plugs electrodes do it... It takes the single spark energy, and splits it up to two or four points (depending on the plug). The result is, 2 or 4 arcs, that are slightly less potent individually, than the single arc of a single electrode plug. However, if the resistance THROUGH the plug body is less than what the single electrode plug was; the sparks will be just as potent. New cars today all use, or should be using single electrode PLATINUM plugs anyway, which offer a more powerful spark than copper plugs did.

You say quickest path to ground huh? Sure, I know that, but with +2 or +4, you now have 2 or 4 paths, and they're all the same. Neither points are going to be quickest to ground, all the points are grounded the same. Not only that, the spark basically has to muscle it's way through the AIR first, if you know how an ARC happens... ok, even with your quick to ground comment; If you have a +4 plug, and say, one of the four electrodes was just a tinge closer to the anode? You would see a brighter arc to just that electrode (more powerful), while the other three would still see a thinner, less potent arc. While the overall voltage remains the same from the center, it is split into the number of electrodes there are. If you use a device that increases the voltage yield; the center anode takes most of that pounding, then the electrodes get a "hotter" spark at each electrode, equal to the "efficiency" of a single electrode plug, with less spark area.

They do not say +2 or +4 are better because they produce a "hotter" spark, they claim it ignites the Fuel and Air better because there is more area of spark to make a better burn of the mixture. What the +2 specs specifically say is; that unlike conventional spark plugs, +2 uses surface air gap technology. The spark from the +2 travels over the surface of the insulator nose first, then arcs across the gaps to the grounded electrodes, for a "longer" spark, without increasing the voltage requirement. They claim better mileage and smoother acceleration.

Well, we'll see what the MPG is now, I know what I have been getting. It does feel better as far as acceleration, but, as I said, a NEW set of plugs in any case will help that, and smoother idle...

 

[Awww KJ]

Keep typing.

 

[blue_kjR417]

Well, I under went the chore of replacing the spark plugs...

All in all, was fine, just had to remove the intake tube...

Why'd you remove the intake, I changed mine about 3 weeks ago and didn't have to disassemble anything but the coils to get to my plugs...

 

[blue_kjR417]

Is $40 or so a "cost" to really dread for a replacement coil pack at the dealer? Oh, and wholesalemopar.com has them for under $30?

I replaced my #6 coil for $24 at Advance Auto Parts, it wasn't a Mopar part but looked identical and works fine.

 

[sleeve]

I think PS (powerslave) had to pull his intake tube because he has that "T" shapped intake thing. I would imagine that covers up some of the access to the plugs and the 10mm retaining nut.

My only comments:

1) a few years back someone on the lost boards tried the +4's and had pretty dissapointing results. Not saying that what you wrote wouldn't work - but just as info.

2) The cheapest way to get coils for your plugs is at the Junk Yard or via the for sale section. A little bit of searching and I was able to round up 2 spare mopar coil packs (new / never used) and I only paid $15.00 for each one. Not that I'll ever need them, but if I do....

3) I tried iridium plugs. They did OK but no better than the standard Autolite single platinum's that fit the KJ oh so nicely.

 

[Powerslave]

Keep typing.

Ok, read on...

Why'd you remove the intake, I changed mine about 3 weeks ago and didn't have to disassemble anything but the coils to get to my plugs...

My intake tube, crosses over to the passenger side, even the STOCK tube does, and it's right in the way of the middle plug, passenger side. The ones on the driver side were pretty easy, and the left side FRONT was easy. The other two were just moving things around. I used the stock tube, and attached it to the aluminum tube with cone filter, you can see my album, there are pics in it with that stuff.

The coolant reservoir was in the way too; I just had to BEND it upward to get that coil plug to lift all the way up, and off. They are about 7" long. If you don't bend the tank up, it isn't coming up far enough to remove. The center one, passenger side, under the intake tube. The plugs are not directly across from each other, BTW, they are staggered.

It was just the passenger side, middle and back I had to put just a little more effort into, that's all. This was how it was for me, some other models are easier.

So, just to, umm, "KEEP TYPING," I decided to change the transfercase fluid too. I wasn't prepared to catch the fluid! I had the catch basin under it, and when I removed that bottom plug, it shot out and totally missed the catch basin. It took about two full quarts of fluid to fill. I had a quart of +4, and some +3 left over, so I used those. Wasn't that fun or easy filling it either, had to bend a funnel, time to buy the flex hose things that screw on.

Still typing: I also put "RE" badging under the "3.7L" badge, so when people ask "What's a 3.7 'RE', I never heard of that." I say "regular edition..." Gets a chuckle or two. Was thinking of placing "CT" after the 4x4 logo...

I found a Bug Deflector for 37.99 locally too, I put one of those on, doesn't look too bad...

Hmm, what else can I drum on about, to appease Mr. Awww KJ, hmmmmm, what else indeed... Can't think of anything off the top of my head, except this ending paragraph that I am just drumming on about, that has no real substance to it, just a bunch of words and phrases put together to keep the typing at a steady pace. More on electricity perhaps? I am very versed in it, as well as electronics, got top notch grades in it. The Air force didn't think I was too stupid either, with a 98% on the ABSVAB... Yeah, I just am so bored that I have to let the words flow from my brain, to some kind of media, else they get all stuck and jumbled in there, builds pressure, and have to drink a few beers to settle me down, ya know?

Oh, but I am rambling, bye for now...

 

[twack]

I still think that there is no need to upgrade the coils or even the plugs really, they do their job and are really effecient. You can get +4s or +whatevers and your not going to see more power or better fuel economy so why do it, unless it makes you feel good to spend money.

 

[moparman]

In general, the hotter the spark the wider the gap. There are cars that are OEM with platinum plugs and a .050 or .060 gap. Some of those have extremely long spark plug life. Clearly the Jeep and some of the Dodges I have worked on do not. .035" gap and copper plugs indicates a relatively low voltage coil. Is it about "cheap to build" or the properties of the combustion chamber? It would be nice to ask an engineer.

 

[Powerslave]

Twack; yeah, I am trying the +2s, they worked well in my Avenger, VERY well. I did not get UNDER 23MPG in that car with all my mods, and that's a 19-27MPG car, as indicated on the window sticker. I was getting 30+ on the highway, and yeah I am feeling it at much less than that now... I got money to burn, so I try all kinds of things, eventuallu something works, then I stick with it.

moparman: Right, the higher the voltage from the coils, the "hotter" the spark is, and the gap can be wider. It does not HAVE to be however, but if the voltage is there, then may as well use it to your advantage. With copper plugs, the coils can be the same voltage, smaller gap because of the inefficiency of the plug itself. If you used copper plugs in the Jeep, you would notice a big difference in idle, and acceleration, that being WORSE... I know people who have ramped up coil voltage to the point where it pitted the piston heads. That said, I had a 2-stroke 4-cly Mercury boat motor, the plugs had no electrode, they arced to the piston heads for combustion.

 

[JeepJeepster]

As far as I know a spark will not 'divide' up into smaller sparks... That just doesnt happen.

 

[twack]

I got money to burn,

then try and find real power and find some pistons that dont have a retardedly high ring.

 

[sleeve]

It would be nice to ask an engineer.

I am an engineer and did spend some time working for Chrysler at their Tech center. To answer your question. The KJ used copper plugs because they are the cheapest.

Chrysler had very tight buget requirements at that time and the plugs are an example of those contraints.

 

[Powerslave]

As far as I know a spark will not 'divide' up into smaller sparks... That just doesnt happen.

What? Have you seen the +2 or +4s in action? Seeing the spark on ALL FOUR or BOTH electrodes? How is that possible, if the spark does not divide up from the main spark, to the two or four sparks to each electrode.

I think you need to buy ONE, and see for yourself. It's only $8.88 for a two pack of +2s. Place it on your block, and plug your coil into it and watch the, umm, MAGIC... It's not that hard to get, physics is physics...

SO, you mean to tell us, that have also NOT even seen one lightening bolt, branch out into smaller bolts from the main trunk? Well, if SPARK does not divide into smaller ones, lightening, when it branches out, must be an optical illusion... Thanks for the science lesson, and now I know the truth about electricity, NOT...

 

[Dave]

I am an engineer and did spend some time working for Chrysler at their Tech center. To answer your question. The KJ used copper plugs because they are the cheapest.

Chrysler had very tight buget requirements at that time and the plugs are an example of those contraints.

That figures. When I changed mine I used the OEM NGK's and they were around $3 apiece at NAPA. Next time I will try the Autolite double platinums.

Dave

 

[sleeve]

I have a set of the Autolite's ready to go in. I just have to find some spare time on the weekend to pull the Iridium's out and put these back in.