Platinum Plugs, whats wrong with them?

[XJ4IV]

Im not defending them Im just curious to know whats bad about them in some engines? I used to have a mazda protege and I installed platinum +4 plugshttp://www.powersparks.co.uk/images/plugs/closeplug.jpg and it gave me considerable more power... and yes I say it did cause it really DID
however I have heard that installing platinums on the 4.0 jeep motor is a bad thing, Why?
I have been having a misfire issue for about two weeks now and today on the way home from work I decided since I can't cheaply diagnose the issue I will just start replacing parts starting cheapest first, Today I bought plugs cap and rotor and upon removing the first plug I noticed they were bosch platinum... they have been doing great. I feel my jeep had plenty of pep for a engine with 230k miles. I havent driven it yet since the plug replacement to notice any difference. but has the platinum plugs messed anything up on my jeep? I have had this jeep for little over two years now and im NOW finding this out!

[ParadiseXJ]

There are four spots from the spark to jump to the tip (I'm not an engineer, so I don't know the proper names) but it's either going to jump from the shortest, or most convenient spot (least line of resistance).

With four "spots" your spark is spread out and/or weak on all four. Litle skinny spark lines, fine on a nice tight ricer, but not on a chunky ol' 4.0.

Get a single electrode plug, Champion Truck Plugs, if possible. It'll fatten and snap up that spark making for better, faster and hotter combustion.

Plus, you'll save money and aggravation.

[XJ4IV]

When you say truck plugs what exactly do you mean? I just got what AZ gave me and they are Champions...

[4.3LXJ]

I run those in my 4.3 They do give me more power over even the E3 plugs. I read an article in a truck mag that stated they got an 11% increase at the wheels on the dyno. I ran them in my 2.8 when I had it and they added 1000 rpms on the top end with the horsepower to go with it.

I have seen them fire when out of the chamber and they give a very intense deep blue spark even when cranking.

[Mudderoy]

There is a method of putting the spark plugs in called "indexing". Basically that means that you are getting the gap directed towards the intake valve. The idea is to have the spark ignite the air fuel mixture better, giving a more complete burn and more power.

The plugs with more than one cathode basically gives you a better chance of getting the INDEX correct. Hence the increase of power, and emissions should improve as well.

I only heard this story once, so feel free to jump in and correct me.

[4.3LXJ]

I think after running these plugs that indexing is a non issue with these. The real benefit is the intensity of the spark and the size. The spark comes from all electrodes and is a round ball of electricity about 1/8" in diameter. Also there is no sizzle or snap. It is totally quiet which surprised me. This is with the stock Chevy coil too.

[Mudderoy]

I think after running these plugs that indexing is a non issue with these. The real benefit is the intensity of the spark and the size. The spark comes from all electrodes and is a round ball of electricity about 1/8" in diameter. Also there is no sizzle or snap. It is totally quiet which surprised me. This is with the stock Chevy coil too.

Well that was what I was trying to get across. You don't have to index the spark plug because of the multiple cathodes. Of course to get a bigger spark you need more power being supplied to the spark plug.

[4.3LXJ]

Well that was what I was trying to get across. You don't have to index the spark plug because of the multiple cathodes. Of course to get a bigger spark you need more power being supplied to the spark plug.

That is the way I would do it old school. Bigger gap and coil. But apparently these engineers know something I don't. I saw it spark while cranking and couldn't believe it.

[pvt.Tadpol xj]

When you start talking about platinum plug's it has something to do with a diffrent spark-plug heat range. And the diffrence has a lot to do with your own personal driving condition's,and of course are you running a stock Ign. or a super stock Ign. I have a very good write on this topic somewhere when i find it i will post it.. But from all my experince if you are running a 4.0 6 everybody recomend's Champion's...O.K. i found the site.... :link: (http://www.centuryperformance.com/spark-plug-tech-spg-26.html)

http://www.centuryperformance.com/images/acc/u_g4.gif

[XJ4IV]

I run those in my 4.3 They do give me more power over even the E3 plugs. I read an article in a truck mag that stated they got an 11% increase at the wheels on the dyno. I ran them in my 2.8 when I had it and they added 1000 rpms on the top end with the horsepower to go with it.

I have seen them fire when out of the chamber and they give a very intense deep blue spark even when cranking.

When you say you run THOSE... which are you referring to?...
I noticed a considerable LOSS in power today by switching to the copper ones and MORE constant misfire, I know my PLUGS are not the issue... So I replaced the plug wires today with 7mm bosch wires... and as soon as I back out it was missing again... any ideas? its not missing ALLLLLL the time like every revolution but sometimes it will go like ten in a row then stop for a few then come back on for a few then stop again when I give it throttle it will eventually stop fairly fast like within2 seconds.
PVT. tadpol when you ask HOW I drive... Im aggressive I drive in traffic alot and basically Im the guy who really DOES drive it like I stole it

[4.3LXJ]

When you say you run THOSE... which are you referring to?...
I noticed a considerable LOSS in power today by switching to the copper ones and MORE constant misfire, I know my PLUGS are not the issue... So I replaced the plug wires today with 7mm bosch wires... and as soon as I back out it was missing again... any ideas? its not missing ALLLLLL the time like every revolution but sometimes it will go like ten in a row then stop for a few then come back on for a few then stop again when I give it throttle it will eventually stop fairly fast like within2 seconds.
PVT. tadpol when you ask HOW I drive... Im aggressive I drive in traffic alot and basically Im the guy who really DOES drive it like I stole it

I have heard people say their XJs do well with these and E3s and others that say they cause theirs to miss and it is a mystery to me why. I think it might be something to do with Renix vs non Renix, but I have not been able to nail that one down.

[XJ4IV]

Still not specifying which plug your talking about... am I ok to run platinums or platinum +4's

[4.3LXJ]

I have the platinum +4s. There is also an iridium +4 but I don't know anything about them.

[XJ4IV]

so the +4's really DONT hurt the engine? Im Kinda bummed cause I bought these regular copper plugs yesterday and today I noticed a loss in power... kinda bummed about that

[4.3LXJ]

I don't think they hurt the engine. I have not heard of it happening. Your engine will run a little hotter though from more complete burning of the gas mixture

[pvt.Tadpol xj]

When someone say's truck plug's that simply mean's the way some auto part's catergorize spark plug's . When you ask a part's dealer for Champion plug's for your Specific YR. & Model Cherokee they know exactly what champion plug to give you. I have been thru 3 Ign. Coil's in one year. The one i'm running now came from Napa and it cost twice as much. But my 91 is doin pretty good.. Are you sure you have a good Ign. Coil.? Are you sure you have a clean fuel filter..

[93gc40]

IMO, there is nothing wrong with them. They just cast too much and provide no real benefit to an XJ motor. If a part doesn't work any better, why pay 3-4X more?

[XJ4IV]

OK so I took the "heap" to the stealership and they Diagnosed for only $50 which is WAY better than it used to be at a dealership. anyhow come to find out I have an issue with the wiring for cylinder 6 ... so I opened the loom up to see if there was a wire that was melted or any other way damaged and HOLY crap there was like 60-70 wires in there....
does anyone know what a way to tes if its the injector itself? other than replacing it meaning like putting a voltmeter to it and seeing if it registers any ohms or volts or anything?

[4.3LXJ]

OK so I took the "heap" to the stealership and they Diagnosed for only $50 which is WAY better than it used to be at a dealership. anyhow come to find out I have an issue with the wiring for cylinder 6 ... so I opened the loom up to see if there was a wire that was melted or any other way damaged and HOLY crap there was like 60-70 wires in there....
does anyone know what a way to tes if its the injector itself? other than replacing it meaning like putting a voltmeter to it and seeing if it registers any ohms or volts or anything?

That is the only way I know to test them. It can also be dirty, which would cause a misfire too.

[XJ4IV]

So i did some tinkering around and got annoyed with it all and decided to wire the aux fan into the Ign. instead... I GUESS while doing that I moved some wires around and guess what... no more misfire... I drove it about ten miles city and ten miles highway back which is more than enough to get it to start missing again and it ran smooth the whole time...
We'll see how long this lasts!!!

[Thomass]

Original introduced by the Alfa Romeo factory, for their all aluminium engine.
I used them in mine ALFA 33 (sud) and ALFA ROMEO SPIDER 04/96 (other spark plugs wouldn't perform as good)
Also in mi rig, a 1989 XJ they make the engine run smoother, cleaner and most of al, : readings show that there are lesser unburned fuel fumes than with single point plugs :
I use NGK BKR6EKPA,

Thomass

[4.3LXJ]

Don't you just love it when you fix something and you don't know what you did.

[pvt.Tadpol xj]

I have never heard proof that pltinum will harm your 4.0.. But everybody swear's by those Champ's. I do think the bosh will raise your cylinder cumbustion temperature's...

[XJ4IV]

I have never heard proof that pltinum will harm your 4.0.. But everybody swear's by those Champ's. I do think the bosh will raise your cylinder cumbustion temperature's...

LIKE A LOT... I installed the Bosch platinum 4's yesterday and OMG I was on the way home from work today and my temp crept into the red... I will be re-installing the copper ones tonight