Automatic analyzing the cylinder pressure waveform
2 posts • Page 1 of 1
The pressure in the cylinder during the exhaust stroke (Fragment shown at number 1) will be at the level of the horizontal blue line only if the atmospheric pressure is equal to the normal atmospheric pressure at sea level (760 mmHg or 100kPa).
Most likely, you are not at sea level, but higher, and, accordingly, the atmospheric pressure in your region is somewhat lower. Therefore, the pressure graph here is slightly lower.
You are mistaken: here the vacuum in the cylinder during the intake stroke is in order.
The fragment shown at number 2 looks like a good motor.
The distortion of the pressure graph in the area shown at number 3 may indicate a weakened bronze bushing of the exhaust valve.