1997 Wagon R: No. 3 plug burns black

1997 formula Suzuki wagon R model: E-CV21S engine model: F6A turbo

An engine that only the plug of No. 3 cylinder burns black

Although it got stocked at the car inspection, if you check the plug, only plug 3 is burning black. If burning is done normally, plaque should burn a little brown without burning black. Therefore, the following inspection was carried out.

  1. When compression is measured, 9 kg / cm 2
  2. Sparks are flying strongly from the plug cord for all the cylinders.
  3. The state of the plugs of all the cylinders is normal (except for plug No. 3)
  4. Engine · Diagnosis · code is normal

From the above inspection results, compression and sparks are normal among the three elements of combustion (compression, spark, air-fuel mixture). Therefore, although the mixture becomes abnormal, when the plug is wrapped (fuel adheres) or it is burnt black, the amount of fuel in the air-fuel mixture is large, that is, the mixture is too dense .

If you suspect that there is an abnormality in the injector of No. 3 cylinder, it is conceivable that fuel leakage of the injector itself or long energization time is long.


Injector Inspection

Remove the coupler of the third cylinder injector and turn the fuel pump to check. Then the third plug was not wet so we judged there was no fuel leakage from the injector.

Next, using the fault diagnosis machine, the energizing time of the injector was measured and the following waveforms were shown.

Hitachi Diagnostic Monitor HDM-2000





Reference material

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