Ford Focus>> Ignition system>> Spark plugs>> Definition of operation of the engine on appearance of a candle
It is possible to determine by appearance of the candle removed from the working engine, the engine well or badly works:
- an insulator cone from light gray to gray color — well prepared working mix;
- the cone of an insulator of white color — too poor working mix, probably, the wrong moment of ignition, is faulty the control unit. Check concentration of CO2;
- a raid of black color in the form of a soot — the wrong kalilny number, too rich working mix. Check concentration of CO2;
- oil traces on electrodes — are damaged piston rings, plugs of valves, maslosjemny caps. Fuel and oil mixing is possible. Replace candles, oil and fuel brand. Again check external a type of candles.