1. Choke: The choke is a butterfly valve located in the carburetor or throttle body of the engine. During cold starting, the choke is partially or fully closed to restrict airflow into the engine. This restriction creates a richer fuel-air mixture, which is necessary for easier starting when the engine is cold.
2. Cold Start Injector: Some modern fuel-injected engines are equipped with a cold start injector, which is an additional fuel injector specifically used during cold starting. The cold start injector delivers a small amount of extra fuel into the intake manifold or directly into the cylinders to enhance fuel vaporization and improve cold starting.
3. Glow Plugs: Glow plugs are heating elements typically used in diesel engines, but they can also be found in some petrol engines. Glow plugs heat the air in the combustion chamber, facilitating fuel vaporization and improving cold starting performance.
4. Intake Manifold Heater: An intake manifold heater warms the incoming air before it enters the cylinders. This helps vaporize the fuel droplets and prevents fuel from pooling in the intake manifold, ensuring a more consistent fuel-air mixture for starting.
5. Automatic Idle Speed Control: Many modern vehicles have an automatic idle speed control system, which adjusts the engine's idle speed based on various factors, including engine temperature. When the engine is cold, the idle speed is increased to compensate for the richer fuel-air mixture and the increased load on the engine.
6. Variable Valve Timing (VVT) System: Modern engines often incorporate a VVT system that adjusts the timing of the intake and exhaust valves. During cold starting, VVT may advance the intake valve timing to improve cylinder filling and enhance starting performance.
7. Fuel Pressure Regulator: The fuel pressure regulator controls the fuel pressure in the fuel injection system. Cold starting may require a higher fuel pressure to ensure adequate fuel delivery and facilitate better fuel vaporization.
These devices work together to optimize the fuel-air mixture and engine conditions during cold starting, ensuring smooth and reliable engine operation, especially in low-temperature environments.
