Spark plug black soot

[britdog]

Okay I replaced my spark plugs in my 97 gst 3 times now. I first tried autolite platinum. They got a black soot on them so i tried NGK just the standard ones. Again they got a black soot on them. So i tried the NGK Copper, they are now covered in black soot like material. I upgraded my turbo to a 16g this week along with a ported 2g manifold, open o2 dump and had to get an o2 sensor because the old one snapped. Well i got a cel for the o2 sensor and the fuel fram. The car now dies at stop signs and you can smell gas. There is'nt any leaks from what i have found its only when the car is on you can smell gas. I ordered a new o2 sensor and I'm going to see if that helps the stalling. Should i try the NGK Iridium? Any suggestion on what to do next after the o2 sensor? Thanks guys

 

[turbodude]

what kind of tuning are you running, if any?... sounds like you are running extremely rich with the smell of gas and the soot covered plugs

 

[britdog]

Also i do have an upstream o2 sensor it was my buddies he took of when he got an aftermarket one with an aem gauge

I havent tuned anything. I adjusted the boost right on the turbo got it around 7 psi. It did fuel cut at a little bit over 10 psi

I also cant stay at a steady speed say 35mph. When I'm not getting one it and I'm just doing the speed limit it will like bog down or start sputtering. and i have to give it more gas so the (sadly auto trans) shifts to like 2nd and then i can speed up to the speed limit

 

[skatershawn]

Wow.. how long have you had your dsm? Sorry!

The "soot" and gas smell are because your car is running too rich for done reason. The type of metal in the plug isn't going to help you any more than the other. I would save your money and stick with ngk coppers.
Next figure out why your car is running rich, you said something about the o2 so yes at idle that being bad can cause rich conditions so change that out and see what you get.
Do a boost leak test!
And make sure you are gaping them(the plugs) right.
Best if luck to you and keep us updated.

 

[Colt4G63 also]

I'm guessing you have a huge boost leak, or there's fuel leaking into your manifold via an injector or the FPR vacuum hose.

Change the oil, it's probably full of fuel.

 

[britdog]

I've had it for about 4 months. It has done it since i changed the plugs. M buddy just ordered me a new upstream o2 from extremepsi. I'll have it on ASAP. Then wires to the plugs are 4123. I havent tried a boost leak test but when I got the new turbo my buddy said everything was good to go and no leaks. But I'm going to get it tested again.

 

[Nasty Dream]

I came across this the other day: descriptions of the different types of worn and damaged spark plugs, with photos:

Champion - A Complete Guide To Spark Plug Performance

I'll post the description here as well. It sounds like you are running rich, but just to be sure, I would exhaust all the possibilities before confirming your conclusion. It could even be multiple causes.

Soft, black, sooty, dry-looking deposits indicate a rich air fuel mixture, weak ignition or wrong heat range spark plug (too cold). These carbon-based deposits are conductive, much like oil fouling, and will allow the voltage coming out of the center electrode of the spark plug to track down the core nose rather than jumping the gap. This will result in an engine misfire and further aggravate the carbon fouled condition. Check for correct plug heat range. On fuel injected engines, check for sticking injectors, malfunctioning cold start valves and/or circuits. Also check for correct fuel pressure specifications. On computer controlled vehicles, the "limp home" computer mode will always result in a rich condition. Therefore, it is imperative that you check the operation and condition of the on-board computer system. On carbureted vehicles, check choke and choke pulloff, high float level, and needle and seat condition. On all engines, severe vacuum leaks can decrease manifold vacuum, resulting in a rich condition. Weak and/or damaged secondary ignition systems will fail to spark across the gap lowering combustion chamber temperatures and promoting carbon deposits. This condition could also result from continuous low speed driving or poor cylinder compression.