Thoughts on these spark plugs?

[Rebar 911]

Pulled my plugs to chase down a misfire. I’m not sure what the coloration means, can someone help me figure this out?

Cyl 6 has a small amount of liquid that smells like fuel. I’m guessing I’ve got a leaky injector…

I'm curious if you've got an update to this thread. I've got a 2012 LR4 as well and just replaced the first bank finishing the 2nd bank tomorrow. My old plugs look similar except they're NGK and they are the 7C model so have been changed at least once. Hoping to smooth out some rough acceleration and poor fuel consumption. Let me know if it worked for you!

 

[itsaguything]

I wouldn't suspect those spark plugs as the root of your issues.
Clean paper air filters, clean maf and clean throttle body is where I would look first.

 

[Rebar 911]

I wouldn't suspect those spark plugs as the root of your issues.
Clean paper air filters, clean maf and clean throttle body is where I would look first.

Thanks. I did all of those things. After replacing the spark plugs and looking at my fuel trims bank 2 still seems to be off. Though the rough acceleration has tapered off. I'm starting to think it's an O2 sensor.

 

[Rebar 911]

Thanks. I did all of those things. After replacing the spark plugs and looking at my fuel trims bank 2 still seems to be off. Though the rough acceleration has tapered off. I'm starting to think it's an O2 sensor.

Based on the MAF sensor voltage readings I'm starting to think bank 2 MAF is bad...thoughts?

 

[Longtrail]

FWIW - Here are my plugs, removed a few days ago, cylinder numbers are marked, so bank 1 (passenger side) is 1, 3, 5 and 7; bank 2 (driver side) is 2, 4, 6 and 8:

This is all part of the timing chain job, I'm changing the plugs while I'm in there!

 

[Rebar 911]

Thanks for sharing. After changing the plugs, doing a compression test and cleaning the injectors thoroughly my fuel trims have improved but I am still running lean in Bank 1 with some hesitation. Sometimes reaching a combined long-term and short-term fuel trim of nearly 20% when driving. I've read another thread that spoke about in tank fuel filter potentially being an issue but given it's only happening in one bank I'm starting to rule that out. I'm wondering if it is the O2 or MAF sensors though voltage on both reads just fine. Any more thoughts are appreciated!

 

[ftillier]

I wouldn't expect the MAF to cause that since there's a single throttle body, if it were bad it would affect both banks equally. An O2 sensor could be it, though - if the reading is close to normal after the fuel trim take effect maybe it's just off. Can you swap side to side and see if it follows the sensor?

 

[scapistron]

Fuel trims positive or negative? Surprised you aren't getting any misfire codes.

 

[Rebar 911]

Fuel trims positive or negative? Surprised you aren't getting any misfire codes.

 

[Rebar 911]

That's when it has been running and comes to a stop. When I'm driving the stay +/-10% for the most part