while adjusting the valves today (thanks Prolene!!! ) i noticed that the spark plugs's tips and the first line of thread are black.

is that normal?

 

There is always going to be a little marking on them. Worry only if you find oil or severe marking (whole plug black).

 

Mine have rust on the ceramic insulator creeping up from the plug.

 

We're just starting to collect plug reports. These can be important to diagnosing engine problems. So far, they seem to indicate really lean (using traditional standards). I'm guessing this is because it is a ULEV car. Anyone know more about this.

BTW, what you are seeing indicates that the plugs protrude slightly into the combustion chamber. The deposits are the same as what's in the head. Seems normal from your description.

 

Sideways,

When you're talking about the ceramic insulator, are you referring to the insulator that resides in the combustion chamber?

One of the problems with many modern cars is that unleaded gasoline and platinum plugs can be very difficult to read. You tend to get an orangish, corroded looking deposit on the electrode, but I've been told its very normal - I'm no chemist though. For some of my high performance 'race' vehicles, I've actually gone to copper plugs just to make tuning a little easier (running Ir plugs on my CRX now, haven't noticed any orange deposits, so it may not be an issue there).

In terms of our cars running lean, no comment from me yet. This might be a good place to cover proper plug reading technique for some of the newbies. Pulling them out of a car and looking at them often isn't enough. To get a feel for the actual running condition at full throttle, you should do a full throttle pass, and then shut the engine down and come to a "dead-stick" stop. Then pull the plugs and look. Of course, that's not always easy to do if you aren't at the dragstrip :-). Come to think of it now, if we look at plugs from an idling ULEV vehicle, they may be on the light side since the ECU is working pretty darn hard to maintain 14.7:1 A/F ratios (or even leaner?).

UL

 

[QUOTE]Originally posted by ultimate lurker
[B]In terms of our cars running lean, no comment from me yet.

 

I suppose I could scan in a basic chart, My IR's are gapped at .050" and a slightly brownish-red but very clean at magnification. Also have FPR set at 42psi no vacume@idle.

Idle on the S2000 certainly has a special map.

 

my '01 has 6k miles on it right now, i took the spark plugs out yesterday and they look good,
a little bit brown on the tip, no oil etc.

looking good.