HoustonRider

I hope nobody starts a conversation around plug indexing, I don't want to read another 36 pages, lol

I'm gonna get a replacement set of the NGK and pull all of mine. Honestly I'm not feeling the mileage (8,500lb 6.7 diesel and 5,500lb 3.5 gas are getting the same mileage) and the truck at 8100 miles now doesn't feel as quick and peppy as it was when it was new.

Yesterday I also posted about the soot at the exhaust, which tells me its running rich, hence, wasted fuel. Anyone notice a correlation between this and swapping plugs and/or closing the plug gap?

I'm not running any tunes on this truck. Mike set up a 5 Star tune for my Raptor and it was flawless, I'm not messing with this truck at all.

Joewee3.5

I have to clean soot from my bumper twice a week. It's worse than my old diesel. I may try to install my new set of plugs and see what these NGKs look like.

Centexguy

Doesn't matter what plugs you run, you will have soot. Welcome to direct injection. This has been covered multiple times on here. But go ahead and waste your time and money if you so choose.

CoreyMS

Joe, you need to check those things. I have soot, yes, but not on my bumper. That sounds like more than normal.

HoustonRider

I checked all my plugs an hour or so ago, they were all almost exactly .032. They look like they are burning well too, nothing to be alarmed about.





Soot from your bumper sounds excessive for sure.

nemosdad

that plug looks like it's never been fired. You have zero contamination on that plug. Test your coil.

Centexguy

Then all 6 of mine aren't firing because all of mine came out looking like that.

nemosdad

There is minimal carbon build up in the thread area. There is zero build up on the insulator. There is zero degredation on the firing contact area's. That plug in the picture has never been fired. Or if it has been fired, it's been with no fuel. Either that or the plug has .ooooo1 miles on it. No isnulator has ever looked that clean on a used plug.
If yours have that clean of an insulator, you're not burning anything in the combustion chamber.

Joewee3.5

Ate you serious or joking. It's hard to tell sometimes if someone is joking or they don't have a clue what they're talking about.

VoiceOfReason

You need colder plugs. LTR7IX-11 gapped with proper technique to .030-.032". The ethanol/higher octane in the poor quality fuel is raising the combustion temps. The trucks runs stoich to keep the temps down = sooty tailpipe/stumbles.

Nuclear cars, anyone.