Spark Plug diagnosis (pics)

[SteveR6]

What do you guys think, these are the cheapo autolites I pulled out of the car the other day. The rust makes them so much cooler.

 

[andymoraitis]

Steve,

I'm digging the Autolite's. I actually run the same plugs and have better results with them than the NGK's. The burn pattern doesn't show anything unusual and they look to be OK. I'd drop a fresh set in there gapped to .028, but as far as being lean, I don't see any evidence. Just to be sure, hold them under a magnifying glass and look for small metal flecks that would indicate detonation. On a stock setup with stock boost, knock should be the last thing I'd expect, especially with the rich air/fuel ratios the stock ECU is programmed for.

Hope that helps,

Andy

 

[SteveR6]

I just noticed that if I look at the plugs from a little distance they look nice and tan but you get up on them and they look lean and white.

 

[SteveR6]

This car had an AVC-R on it before I bought it. I pulled it off and everything is NOW stock. God knows what boost they were running before I got it.

 

[andymoraitis]

Steve,

Change them out for a fresh set and you should be fine. Mine show tannish white as well and I know the motor's not lean since I can read knock (detonation). Swap in a fresh set, do a few third gear pulls and take them out to have a look. I'll bet they're good.

Andy

 

[ericbev]

I agree with andy.

If you yank a plug and find a nice off-white or slightly tan/gray color and the electrodes still have a decent edge to them (which yours do) then slap them back in. Your insulators (although I cant see them very well) dont seem to have any deposits on them and dont have any discoloration. The heat range and plugs themselves seem to be fine to me, although with the price of spark plugs, it sure is a cheap piece of mind if you deceide to replace them.

 

[SteveR6]

I already replaced them with NGK BPR6ES I pulled those the other day and checked them and they look just like these Autolites do (minus the rust ).