tuning problem?

[s14zenki]

I own a 95 240 with headers,exaust and intake. my question, there is a large amount of black smoke that comes out of the muffler, also when i changed my spark plugs they were covered with black soot. is my engine runnig too rich? if so, how do i lean out the air/feul mixture, any suggestions would be appreciated

[95_240sx]

What octane fuel are you running and plugs and what are they gapped to?

Rick

[TomsMR2]

What octane fuel are you running

if he was detonating from low octane the plugs would be white, not black.

sounds like unburnt fuel to me... you sure you're gapped properly? air filter clean?

[s14zenki]

i'm running 93 octane and i have platinum plugs so they shouldnt need to be gapped right?

[TomsMR2]

depends on the brand.. i do believe ive had to gap platinum plugs..

as a rule of thumb, its always a good idea to check the gap on any plug before installing.. they can get a bit banged up while being shipped etc etc.. only takes a second and is worth the piece of mind btw, gap checkers are like 99 cents.

[jrc90240sx]

What if the gap is corect, and your still running rich? what else could you do? I was thinking hotter plug, and maybe 2 degres advance on timeing? would that work, anything else? also i live in Utah 4500ft able the sea, and run 91.

[jrc90240sx]

and what problems do you think you could have running 10 degrees and not 15? not sure if i was because someone else set the timing, but i just want to ask.

[Aries]

I own a 95 240 with headers,exaust and intake. my question, there is a large amount of black smoke that comes out of the muffler, also when i changed my spark plugs they were covered with black soot. is my engine runnig too rich? if so, how do i lean out the air/feul mixture, any suggestions would be appreciated

Check the ecu for any O2 sensor errors. then try advancing the timing slightly until you can run the car and the motor runs smoothely without leaving black residue/black smoke.

This is an N/A car right?