Why does the Geely Panda experience unstable idle speed during cold starts?
1 Answers
Geely Panda experiences unstable idle speed shortly after a cold start, which can be attributed to unstable data from a sensor other than the oxygen sensor, causing the ECU to repeatedly adjust the fuel injection volume. These sensors include: the throttle position sensor, intake air pressure and temperature sensor, coolant temperature sensor, and engine speed sensor. For a short period after a cold start, the ECU will still ignore the oxygen sensor signal. This is necessary for rapid warm-up and also because the quenching area in the cylinder is at its largest during a cold start. The quenching area can be simply described as the area within the ignited combustion chamber that cannot catch fire due to localized low temperatures, and its size is related to the cylinder block temperature and the mixture concentration. If the oxygen sensor is included in the closed-loop control immediately after a cold start, the engine may stall due to excessively low temperatures, overly lean mixture, and an excessively large quenching area.