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What is cold start enrichment?
An engine starting from cold will require an enriched fuel air mixture. This is to compensate for the condensation of the liquid fuel on the ‘cold’ surfaces in the intake tract and piston crown/combustion chamber and ensure that a combustible mixture is presented at the spark plug for first fire.
Why is a rich mixture needed for cold starting?
A cold engine needs a lot more fuel to get the fire light, as much a two or three times as much fuel depending on the temperature. This is called a “rich” mixture because the relative proportion of fuel to air is higher than the normal or “stoichiometric” ratio or 14.7:1.
What is the purpose of a cold start?
The cold start injector, also referred to as the cold start valve, is an engine management component found on many road going vehicles. It’s purpose is to supply the engine with additional fuel to enrich the fuel mixture in cold temperatures where air density is increased and additional fuel is required.
When starting a cold engine a mixture is required?
It must be vaporized and mixed with air to function well in the cylinder. The vaporization is aided by the heat of the engine and during the compression stroke. In a cold engine, not enough of the fuel is vaporized and the mixture is too lean and an enrichment partially compensates for this.
Why do cars run rich on startup?
To overcome this, more fuel is added when the engine is cold to give a more ideal mixture for starting. During cold start, the more fuel is injected so as to increase the compression ratio of the engine which has effect of increasing the pressure and temperature in combustion chamber.
Does cold start use more fuel?
Why do you add more fuel when the engine is cold?
When the engine is cold, the fuel won’t evaporate properly, so what would normally be a correct mixture on a hot engine will actually be a weak mixture when cold. To overcome this, more fuel is added when the engine is cold to give a more ideal mixture for starting. share|improve this answer.
How much fuel do I need for cold start?
This will generally be less than 300 to 400 RPM so we require a bit of extra fuel to get the engine to turn over, catch and start. Post start enrichment – This is the additional fuel that is injected for a period of time after the engine starts.
When to enrich fuel air mixture for maximum performance?
If you prefer maximum performance, lean almost to roughness then gradually enrich the mixture while noting the airspeed. Maximum indicated airspeed (IAS) will occur when the mixture is at best power. This procedure will require some practice at first, but eventually you will become quite good at it.
When to use the cold start injector in a car?
The cold start injector is there to enrich the fuel mixture of the vehicle during low temperature conditions, such as during cold starts or in cold weather.