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any one run platinum +4 (4 prongs)? Any luck or comments?

i ran the bosch platinum 2+ ... what a waste. they were the correct heat range for the engine, but i still burt up 3 of them in 10K miles ... went with autolite and have been running them for 20K without a hitch .... the older engines really dont like the higher end plugs for one reason or another ... newer engines like the higher end plugs though ....
 

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I ran the +4's for about 6 months now. I run these plugs in truck and i was impressed with them. ON the Jeep though it has been a different story. I started having a random idle...jumping from 450-1200 rpm and figured it was tps, AIC, or some other nonsense. After changing everything i decided to change the plugs over to champion. Pulling the bosch ones out i was suprised after 6 months they were completely fouled. After the champions went in it idled as smooth as ever. I did a lil research and several people say the coil packs dont generate enough power to efficiently spark the +4s. Guys with the distributor may not have this problem but they didnt do well in my jeep. I torture mine and put it through hell keep in mind, but jus figured i would share this with ya.
werd. tons of jeeps have problems with the bosch plugs .. its not just the 4+ .... for the older engines -2002 a regular resistor type plug really si the best thing for the engine.
 

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Knows a couple things...
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For some obscure reason I read a few months ago but forget what it is, there are a number of engines... Jeep included... that don't run well on Bosch's Plus4 and Plus2 plugs. Certainly lots of negative experiences with them on the 4.0L and 2.5L. I did a Yahoo search and found lots of discussions on the problems with the Plus4 and Plus2 plugs so Jeeps aren't the only brand that don't like that particular plug. One of those discussions had a Bosch engineer's comments on what the likely issue was for some engines, I wish I could find that thread now but I can't.

For me, I just avoid all such gimmick plugs which include the Plus4, Plus2, Splitfire, Iridiums, etc. I've had great luck with my Autolite Platinums but you even need to be careful with which platinums you use, if you want the extended life platinum plugs offer. Newer distributorless 4.0L engines are fussy and can only use either double-tipped platinum (platinum on both sides of the gap) or conventional non-platinum plugs. Using a single-tipped (platinum on just one side of the gap) platinum plug on a newer distributorless 4.0L engine will cause problems.

Older 4.0L engines with distributors can run single or double-tipped platinums without problem though there's no benefit to the more expensive double-tipped platinum plugs on that type of ignition system. :)
 

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Drives by Braille
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....Iridiums......
Iridiums are great! Especially for high performance engines with high energy ignition systems(imports with multiple coils packs and upgraded MSD/Accel systems)... They will last a looong time. A friend ran them in his Audi S4 for well over 50k and it didn't even look like they were used!
 

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Knows a couple things...
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Iridiums are great! Especially for high performance engines with high energy ignition systems(imports with multiple coils packs and upgraded MSD/Accel systems)... They will last a looong time. A friend ran them in his Audi S4 for well over 50k and it didn't even look like they were used!
I thought we were talking about Jeeps here. ;)

On the other hand, my plain-Jane single-tipped Autolite platinums looked nearly new with 66,000 miles on them, all still with the original .035 gap. :p
 

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Sorry - but yes, I believe that single tipped plats are the best for our 4.0L/2.5L Jeeps :D
 
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