In an unrelated move, I borrowed a code scanner from AutoZone to check on some emissions related stuff. I noticed the car was throwing a multiple cylinder misfire code... funny. After re-clearing the codes, it threw a code for a misfire on cylinder #1. Hmm... might as well pull the plug and see how it looked.

The plug had a white crusty buildup on it. (Alrighty you pervs, get the laughin' out of yer system now ). I let the engine cool down and pulled the other 7 plugs. Same deal.

From my understanding, this is caused by running too lean or too hot, or both. The car has an XE 224/230 cam and was running with stock injectors for about a year up until this past July. I never checked the plugs because I never saw this code before. Now it has SVO 30# and seems to be doing ok.

I'm going to throw in some cheap-o plugs tomorrow and put some miles on it and start trouble shooting from there. Right now I'm just curious what stuff might cause the type of buildup I'm seeing. Also, any recommendations on gap?

Thanks!

 

Yea, the crusty plugs could mean a couple of things actually but more than likely, youre just running lean/hot. I would put some NGK TR-55's in there. They work great for me. As for the gap, I usually gap mine at about a lil smaller than stock which is .050 I think. I might have the decimal off a place, I dunno, its a holiday. I normally knock mine down to about .047 thanks to the advice of a friend who told me for every x amount of hp you make more than stock, you should close your gap some. I closed mine a lil and while I didnt notice any gain in performance, it did idle a little smoother/crisper.

 

The only time I've had white crusty deposits on my plugs was when I had used a couple bottles of octane booster. I don't know if you have done the same, but the octane booster will leave deposits on everything and I would stay away from it.

 

brandboZ28... the plugs are TR55's. Like I said, we'll see what happens with new ones thrown in there...

 

Go one step colder on the plug's and gap them at .035.There is no need for a "wide" gap as it is good for a tad smoother idle and to sell tune ups--opti,wires and plugs.If you want to replace all these things before it is time or they are worn out- gap at .060.

 

www.gnttype.org/techarea/engine/plugs.html