ThreeHonks

iTrader: (10)

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

old93camaro

iTrader: (8)

looks like to much idling and not enough driving... plugs are not getting to operation temp so they can burn. if you are running tr6 are you over 11:1 cr if so what the gap.... i had the same problem and i had to gap mine at .042 all the wat around for a hot burn and it does not blow out the spark

Gojira94

iTrader: (4)

It'd be interesting to see what could be done with adjusting individual cylinder trim in the tune. Looks way too rich except the front 4 cylinders and even a couple of those look a little too rich... What kind of power are you making, BTW? and what are your compression numbers? Wondering why you went a heat range colder on the plugs, and what you're gapping them at. Range 6 is fine if you're above 11:1 static compression, and you'll want to close the gap .004" for every 50 HP above stock, general rule of thumb. And why such large injectors? You going to add forced induction or nitrous?

ThreeHonks

iTrader: (10)

I have 11.5:1 compression. They are gapped at .035" This still does not explain why some look white, others look OK, and some are black

ThreeHonks

iTrader: (10)

I am making approx. 450 to the tire through a stalled auto/9". My injector duty cylce with those injectors is over 80% as is

Gojira94

iTrader: (4)

Damn, nice numbers! That explains the 42#

Drive the **** out of it and log a little and let your tuner see what's going on.

ThreeHonks

iTrader: (10)

Thanks!

Im not sure if thats what I feel the safest thing is to do.

I am wondering if something could be amiss with my LS1 pcm converison or how it was tuned. I have my hptuners tune file if anyone needs to see it. I am not very knowlegdeable when it comes to tuning, but can the LS1 pcm be tuned to adjust cylinder by cylinder spark and fuel?

Gojira94

iTrader: (4)

OBD1 LT1 PCMs have the ability to adjust each cylinder in the individual cylinder fuel trim multiplier table; I'd believe the LS1 PCM would be at least as flexible.

StealthFormula

iTrader: (35)

I'm actually having the same issue currently. Only difference is that my #4 plug is clean. FWIW I was running Autolite 104's gapped at .040" for just a couple weeks until it happened to me. I've been running the 104's gapped at .035" for a couple years now with my setup and have never seen this, not sure if the looser gap had any ill effects. I cannot figure out the issue for the life of me, the ignition components have the proper voltage and the car runs well. Typically when plugs are carbon fouled there is an issue with the ignition.

I went ahead and bought some new MSD wires and some TR6's (should of had them initially) so once they come in the mail I will toss them on and see what happens. If I figure it out I'll let you know and I'll be checking this thread to see if it gives me any ideas.

ThreeHonks

iTrader: (10)

I was told by my tuner that it could be a fuel distribution issue and that the rear injectors are seeing more pressure somehow. He said the PCM can adjust fueling bank to bank, but not front to rear.

EDIT: I was just told my Injuneer and my tuner that if the FPR is bad it will cause the rear cylinders to see more pressure and dump more fuel. It is making sense to me because #7 is by far the darkest plug and that is the cylinder that is cloest to the pressure regulator. Maybe this is your problem too Stealth!

quik95lt1

iTrader: (7)

that is definatly an issue......its not caused by just idling......mine have never got like that from just idling.......also as for the gap you can run .040-.045 with no issue espically if you are running a good ignition....i ran .043 on my 11.2:1 355.......my 14:1 383 is at .042 with no issues.......as for what we' are seeing its very possible it could be a fuel distribution issue....how is it plumbed? also if you have the 24x on it it should be in sequential mode which means it CAN be tuned individually....if you are in batch fire it cannot.......id be curious to see what the tune looks like id check out the tune before i go beating on it too much more.....dont want to be taking any chances

ThreeHonks

iTrader: (10)

I attached the tune file.

I have stock fuel rails and plumbed in the stock style with a stock regulator (never been replaced).

Do you think I would be better off running a tr-55 over this tr-6 or should I just open the gap on the 6's?

quik95lt1

iTrader: (7)

well thats something your going to have to play with......to be honest with you i thing a TR5 would be fine i ran one in my motor and you are almost the same compression as it was.......as for the regulator it may be time for an upgrade.......even parallel plumbing the fuel rails may not be a bad idea at this point as well........but as for those plugs it looks like a tuning issue..

zz17iroc

iTrader: (1)

Are you still using an LT1 style intake? If so I used to have mini ram which are very similar in design to a LT1 intake And I was having the same issues with my spark plugs. It ***** down to unequal air distribution with the TB location being directly in front of cylinders 1,2,3, and 4. So the further back the air flows the less amount of air cylinders 5,6,7, and 8 receives causing a rich condition for those cylinders. Yes you can control the pulse in each injector, but the fact still remains unequal air distribution equals less power. That's one of the main reason why some people have better performance with single plane set ups just as I did. I swapped to an Accel Pro Ram and I'm so happy I did.

AChotrod

iTrader: (17)

You mean JIM aka Intimid8 at Speedinc??

StealthFormula

iTrader: (35)

That is EXACTLY my issue, I'm glad you mentioned that because I bet it is the FPR.

Could you give some recommendations? I've never looked into FPR's so I really have no idea if I want an adj. or non-adj. or what brand etc.

quik95lt1

iTrader: (7)

Well if you want to go with one that will mount right in the location of the stock I'd go with this aeromotive one......problem is its pricey but its worth it
http://www.summitracing.com/parts/AEI-13107/

ThreeHonks

iTrader: (10)

No, its a different guy, same SN.

quik95 & Stealth - I just ordered a new OEM regulator and a set of tr-55 plugs today. i will post back and let you know if it helps.

Mike- what do you think I should gap these at? im thinking .050" since I have a good ignition system with truck coils and MSD 8.5 wires. Remember, its an LS1 pcm

96capricemgr

iTrader: (1)

Let me guess you have somehow defeated the IAC circuit. Be it a 58mm without the bypass drilled or a monoblade?

AChotrod

iTrader: (17)

Got ya! Didnt know there was multiple tuners with the same SN.
96 what do you mean bypass drilled on a 58?