Why does the Nissan Sylphy have high RPM during cold start?
1 Answers
The Nissan Sylphy having high RPM during cold start is a normal phenomenon. Since the engine temperature is low at startup, the vehicle's ECU increases throttle opening and fuel injector volume to help the engine reach operating temperature faster. Typically, the engine RPM will begin to decrease after 30 seconds, so there is no need for concern. More details about the Sylphy's cold start are as follows: 1. During a cold start, the engine temperature has not yet reached its optimal operating level. In this situation, the fuel injectors automatically increase fuel delivery to raise the RPM, with idle speed ranging between 1200-2000. After idling for about a minute, if the RPM drops below 1000, it is considered normal. Avoid prolonged idling during cold starts, as this can lead to carbon buildup in the engine. 2. During a cold start, engine components are not fully lubricated, and the operating temperature has not reached its optimal level. The fuel injectors will automatically increase fuel delivery to raise RPM. Generally, idling for 30-100 seconds is sufficient before driving. Keep the speed below 30 km/h and drive slowly for 2-5 minutes until the engine reaches its optimal operating temperature, after which normal driving can resume. 3. For the Nissan Sylphy, prolonged idling during cold starts offers no benefits and is more likely to cause carbon buildup in the engine, potentially damaging it. After a cold start, wait 30-60 seconds for the RPM to stabilize before driving. Until the coolant temperature reaches normal levels, drive at low RPM and slow speed (keeping engine RPM below 3000), and avoid aggressive driving styles like heavy throttle inputs.
