Spark Plugs - Should Have Listened to Jerry

Pillswoj · 04-03-2008, 11:15 AM

Got my Jeep in November, at 75 k I believe it still had the original plugs in it, Champion 2412.

I February I finally got around to pulling them gap was over 0.06.

I had read that Champions or Autolite AP were the way to go but they didn't have them locally. Decided to try the Bosch Platinum 4's.

I installed them and noticed that I had power back in the low rpm range. Great, the guys on the forum are wrong

They were in for 6 weeks and about 1000 miles, noticed that idle wasn't quite right and it took a bit longer to start up. Pulled the plugs and found massive Carbon build up.

Needless to say I have ordered the Autolite AP's from Napa.

Next time I Listen

Jeff

fromme · 04-03-2008, 11:29 AM

So you got over 70,000 miles with the stock plugs, but for whatever reason you went with something else to replace them? Why? I'd use the same thing that worked for me the first time. Autolite APs (whatever those are) may work, but why take the chance instead of going back with the others?

Crashnburn80 · 04-03-2008, 11:29 AM

The Bosch plugs are great plugs, just not in our 4.0.

**BYuen** · 04-03-2008, 12:01 PM

lol wow that's insane. Thanks for sharing that piece of info.

The Big H · 04-03-2008, 12:20 PM

Very good info. I'll make sure I go with the Autolite.

DaOne · 04-03-2008, 12:21 PM

Are Champion truck plugs among the best for the 4.0L?

Pillswoj · 04-03-2008, 12:40 PM

Jerry has stated many times the the Champion Truck plugs are very good but he prefers the Autolite AP985 for their added longevity, this is for TJ's with Distributer, for Coil Packs I believe it is the double platinums APP 985 that are needed.

Jeff

**BYuen** · 04-03-2008, 12:46 PM

Quote:

Originally Posted by DaOne

Are Champion truck plugs among the best for the 4.0L?

They're what I run. Never had any issues.

Wif · 04-03-2008, 01:30 PM

Quote:

Originally Posted by Pillswoj

Got my Jeep in November, at 75 k I believe it still had the original plugs in it, Champion 2412. .... They were in for 6 weeks and about 1000 miles, noticed that idle wasn't quite right and it took a bit longer to start up. Pulled the plugs and found massive Carbon build up. ....

They look like the engine is running really rich .. maybe you have other issues.

xltj · 04-03-2008, 01:42 PM

Hmm I should use this post to inspire me to change my spark plugs. Haven't done that yet and i'm at 67k miles

sideout · 04-03-2008, 02:17 PM

I had the bosch platinum 2s in my Jeep when I bought it. The Jeep would just die at idle. It would start right back up, but it started to get worse. I was troubleshooting EFI, when I got good advice here in JF to start with the basics. So I did a tune up with regular champion plugs and the problem went away. Runs like a champ now. I have a 4.0 with the coil packs.

Pillswoj · 04-03-2008, 02:50 PM

Quote:

Originally Posted by Wif

They look like the engine is running really rich .. maybe you have other issues.

Yeh it looks like it, however the Champions I took out were as one would suspect, a light tan deposit but generally clean, I will check the New plugs after a month to see how they do.

**Skyryder** · 04-03-2008, 02:59 PM

With all this plug talk I changed mine too, these had, I would guess, 59K as they were in when I bought the rig, Champion RC12LYC and was running fine but looks like they were due. Put in a fresh set of Autolites and the pick up seems to have improved.

AWa1martGreeter · 03-12-2009, 06:26 PM

Going to change mine this weekend! Thnks for the info.

**2jhanna** · 03-12-2009, 06:36 PM

I just changed mine Monday, used APP985. Old NGK's had 60-65 gap.