Why did my AC Delco plugs turn brown ?

[cottonpicker14]

Posted this in the TTA section, but didnt get any responses. Maybe someone here can help
About 500 miles ago I changed my plugs (AC Delco R42LTS, gapped at .35) on my stock TTA.
Since then, I have been running a combo of 93 and 104 octane for a 98 octane, using a turbo tweak chip programmed for the 98 and 18 lbs of boost.
I had a small miss which turned to be a bad wire, but when I checked my plugs today, all the plugs were brown. The porcelin, electrode, etc was a brown color, almost the color of rust.
Any ideas whey all the plugs with only 500 miles would turn brown ?
Here is a link to two photos of them

http://img.villagephotos.com/p/2002-12/74500/DSCF0906.JPG

http://img.villagephotos.com/p/2002-12/74500/DSCF0910.JPG

Thanks

 

[TurboBuickSix]

Did you add anything else to your fuel like injector cleaner or "octane booster"? The 104 is actual fuel and not that 104+ booster stuff right,sorry if that sounds like a dumb question but I just want to clarify.

 

[bruce]

Posted this in the TTA section, but didnt get any responses. Maybe someone here can help
About 500 miles ago I changed my plugs (AC Delco R42LTS, gapped at .35) on my stock TTA.
Since then, I have been running a combo of 93 and 104 octane for a 98 octane, using a turbo tweak chip programmed for the 98 and 18 lbs of boost.
I had a small miss which turned to be a bad wire, but when I checked my plugs today, all the plugs were brown. The porcelin, electrode, etc was a brown color, almost the color of rust.
Any ideas whey all the plugs with only 500 miles would turn brown ?
Here is a link to two photos of them

http://img.villagephotos.com/p/2002-12/74500/DSCF0906.JPG

http://img.villagephotos.com/p/2002-12/74500/DSCF0910.JPG

Thanks

Certain gas additives, will do that. Shell for years (depending on location) was bad for that. With prices going as high as they have, the refineries are probably using anything they have on hand, to get it into line with the EPA mandates.

If you mean 104 Octane Booster, that will do it.

That said, richness, too cold of plug will also do that.

 

[cottonpicker14]

Thanks for replying
The 104 is Sunoco Race gas unleaded. Never added any octane booster.
When I changed the plugs 500 miles ago. I was running 93. I then started adding the 50/50 mix of 93 and 104 to up the boost. I was running rich, at around 890 at WOT.
I had also installed a Caspers chip set up for 93 when I did the plugs 500 miles ago then decided to use 104 Sunoco and 93 combo for more boost and kept using the Casper chip
Last week my turbo mechanic installed Erics chip setup for 98 octane, we put in new 30 lb green stripe injectors (had the factory 28 lb). It has a miss while we drove meaning that at cruising at around a constant 50 or 60mph, it would sputter. Changed the wires and no problem
When he pulled the plugs to checked is when we found all were brown.
Does this help anyone in figuring out why ?
Thanks

P.S. all my scanmaster readings are now in range since the tune and injectors, 43.5 fuel pressure (hose off) and running around 790 at WOT at the top of 3rd gear.

 

[cottonpicker14]

ttt

 

[MSDGN]

It's an octane booster that Sunoco adds to their 104 unleaded fuel...the manganese(MMT) content is what turns the plugs a rust color...I had the same thing happen when I used Sunoco 104...so I called them and talked to one of the Tech guys...he said "Yep we add MMT to get the 104 rating"...I don't think it hurts anything...but it may cause premature failure of your O2 sensor as it gets coated with that stuff...I stopped using it...

 

[Duff73]

Gap of plugs

You may want to gap your plugs a bit tighter as well if your running higher boost and octane other than stock. Usually a gap of 35 is good for stock boost and regular premium octane. Lot of guys goto a gap of 32 as they increase boost and octane.

 

[cottonpicker14]

Thank you for the help. I guess its time to go alky and get rid of the Sunoco ?

 

[Grumpy]

hmmmm ...guess I am not as dumb as I look :biggrin:

 

[krom]

I run the 104 all the time and my plugs look like that.