What are the reasons for cold start engine speed below 1000 rpm?

[VanEva]

Reasons for cold start engine speed below 1000 rpm include: insufficient lubrication, engine carbon buildup, and slow oil temperature recovery. Insufficient lubrication: During cold starts, due to low temperatures, the oil's fluidity is poor, and the engine hasn't been fully lubricated, which may result in lower engine speed. Carbon buildup: If there's carbon buildup in the engine, the speed may drop below 1000 rpm. It's recommended that car owners regularly visit auto repair shops for carbon cleaning to ensure normal daily driving. Slow oil recovery: During cold starts, low temperatures cause the engine oil to become viscous, leading to slow oil recovery. This results in cold start speeds below 1000 rpm. During cold starts, when the engine temperature hasn't reached its optimal working temperature, the fuel injector will automatically increase fuel supply to raise the engine speed. Engine speeds between 1200-2000 rpm are normal during this period. After idling for a few minutes to warm up, the engine speed will automatically drop below 1000 rpm. Engine speeds between 500-1000 rpm are considered normal. After running for a while, the car's computer will automatically adjust the speed.