Spark plugs burning uneven - Pics Included!

[ThreeHonks]

I just got my motor back together and was checking a few things out, decided to pull the plugs and this is what I found:



I have never seen anything like this before. As you can tell it is a DRASTIC difference. Please pay attention to #7 plug as it is soot black.
What could be causing this? The motor (and plugs) only have about 40 miles on them including some WOT pulls.
DETAILS ON MY SETUP:
-heads/cam LT1
-has the LS1 pcm conversion 24x system
-has NGK TR-6 plugs
-has 42lb. green top injectors
-tuned in speed density by Dr. Phil INTIMID8

[Fox Slaughter]

Could it be the cylinders aren't getting the same amount of fuel due to dirty injectors or fuel rail?

http://www.superstreetonline.com/tec.../photo_05.html


http://www.ngksparkplugs.com/docs/te...fe%20Plugs.pdf <-- Talks about using Single Platinum and Iridium plugs with uneven wear.

I have no idea just throwing thoughts out.

[JoeliusZ28]

yea, did you ever have your injectors flow matched?

[MunsterZ28]

yea, did you ever have your injectors flow matched?

x2?

[DETROITMUSCLE]

threads looks pretty clean so its not oil unless you have major valve seals going which we ruled out before too. I'd say its definitely fuel related. Have Phil flow those injectors would be my next step.

[meissen]

Is all the gunk around the base of the threads a sealant or sludge?

[DETROITMUSCLE]

Is all the gunk around the base of the threads a sealant or sludge?

looks like anti-seize

[ThreeHonks]

yea, did you ever have your injectors flow matched?

yes, I bought them used, but they were suppossedly flow matched. I flipped the injectors around and it is still the same pattern, so it is safe to rule out the injectors.

Is all the gunk around the base of the threads a sealant or sludge?

It is just anti-seize. Th plugs look fine, oil-wise, but they are just burnign uneven. Some look lean and others are rich.

I talked with Phil my tuner and Injuneer over on Camaroz28 and they said it is a fuel distribution issue, and that the fuel pressure regulator could be leaking which would cause the rear cylinders to get more fuel. This looks like it would make sense to me...

Especially seeing that #7 is the closest cylinder to the FPR and it is by far the darkest.

do you guys agree/disagree with this? remember, the car is running amazing. not missing and it is making great power

[meissen]

FPR makes sense. If you yank the vacuum line off that goes to the FPR, sniff the vacuum line and see if you smell fuel. Usually the vacuum line will be wet with gas when the FPR is going.

[DETROITMUSCLE]

seems to make sense to me, it def a fuel issue IMO. Switching the injectors won't tell the whole story with the same plugs though. Those won't change color for a while you'd have to swap in new ones to fully test that theory but I'd check out the regulator as well.

[ThreeHonks]

seems to make sense to me, it def a fuel issue IMO. Switching the injectors won't tell the whole story with the same plugs though. Those won't change color for a while you'd have to swap in new ones to fully test that theory but I'd check out the regulator as well.

I had the same exact pattern before I tore my motor apart and I put the injectors, wires and coils all back on randomly this time and the same exact pattern exists. So I can rule out being an injector, plug wires, or a coil. I also OHM checked the PCM injector and coil drives.

[DETROITMUSCLE]

well what are you waiting for go get a new regulator and slap it on.

[ThreeHonks]

well what are you waiting for go get a new regulator and slap it on.

im trying to decide if I should just go buy another stock one or get an adjustable billet one. I have no idea which is better. I need to research

[meissen]

With all that's done with your car, an adjustable one wouldn't be a bad idea even if you're just putting it to stock settings now -- atleast in the future when you're ready to adjust it you'd have the ability.

[ITSSLOW]

I'd say its something messed up with the Fuel Pressure Regulator. Notice the rear plugs are all darker and seem to lighten up as they go out. My guess would be that the FPR is closest to #7. Replace it and have the injectors matched.

*edit* nevermind! Guess I should read more than the first post before giving my .02. lol