1993 camry Spark Plugs covered in snow deposit

Yes, do change the air filter. ECU controlled engines are not like a carb engine where a dirty filter makes the engine run rich. The ECU tries to compensate for the amount of air, and tends runs lean. You should also check the O2 sensor and cat converter. All these can conspire to lean running.

Stewart DIBBS

Hmmm, that is counter intuitive, clogged air filter making it run lean. Never would have guessed. So the white snow like deposit on the plugs IS symtomatic of running lean?

A clogged air filter will not make the system run lean because the air flow meter measures the air exiting the filter. If the air flow was measure prior to entering the filter, then the system might run rich - but only if the feedback system was not functioning.

Check out this page from the Bosch automotive web site for pictures and descriptions of spark plug conditions:

meter measures >the air exiting the filter.

That is how i thought it was set up. . . . . . I compared the plugs to the color photos in the back of my haynes manual, and I couldnt find one to match them. Then I was told (because of the plug coatings) that my engine was running lean and burning holes in my pistons!. . . . so I thought it wise to seek a 3rd and fourth opinion. They seem to match the picture of the normal running plugs on the bosch web page. Thanks

I wouldn't worry too much about a fine white ash on the plugs. I'd bet that if you switch to Toyota genuine plugs, you wouldn't see as much white stuff.

Your concerns remind me of a customer who came to our office with concerns about the plugs on his Starlet. The receptionist called me up to the front desk to speak to the guy, who was holding a spark plug in a rag. He explained his concerns and handed me the plug. What he didn't tell me is that he had removed the plug in the parking lot and that it was still HOT! Luckily, I dropped it on a stack of papers on the receptionist's desk and not on the ceramic tile floor! A quick re-gap and he was on his way.

Yep

David

mcndrew wrote:

Thanks,

The book, and toyota said to put platinum plugs in it, so of course I didnt. I dont plan on getting more then 50k more out of the car, so I dont plan on spending 7$ a plug. Ordinary plugs arnt going to melt into the cylinder or anything or they (I already have them in there, and it has run just fine for 2-3 hundred miles)?