Spark plugs are carboned up after little mileage

ericem · Post by **ericem** » Thu Oct 25, 2007 9:17 pm

Hi I want your opinion on what is wrong. I have replaced the plugs 3 times in 15,000km and they always come out looking the same way with a lot of carbon on the plug. Tried NGK g and v powers with same result.

555BCTurbo · Post by **555BCTurbo** » Thu Oct 25, 2007 10:05 pm

Either your car is running rich, has low compression, or has oil control problems...

ericem · Post by **ericem** » Fri Oct 26, 2007 12:28 am

Ok car doesn't burn oil and vacuum gauge is showing 21 which is good so compression and timing belt is good. Car definitely does seem to be running rich. I replaced the ECU temp sensor, knock sensor. Only things left to replace I guess is MAF sensor and oxygen sensor.

quicklook · Post by **quicklook** » Sat Oct 27, 2007 2:09 am

is air filter clogged?

ericem · Post by **ericem** » Sat Oct 27, 2007 3:26 am

Just replaced it.

BXSS · Post by **BXSS** » Mon Oct 29, 2007 8:45 pm

Carbon on the plugs = "overfueling" - its rich.

The rich condition may be caused by MAF, coolant temp, O2 sensor, high fuel pressure... - the fuel injected is just too much fuel to burn.

A less likely cause for this may be a weak ignition system - where the correct amount of fuel goes into the c-chamber, but the spark produced is not strong enough to burn it properly.

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Spark plugs are carboned up after little mileage

Spark plugs are carboned up after little mileage