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. It plays a key role in the performance, fuel economy, and starting characteristics of the vehicle, so when it does have issues the problems can detract from the overall drivability of the vehicle. Usually a problematic cold start injector will display a few symptoms that can alert the driver that a potential problem has occurred and needs to be serviced.
1. Hard Starting
One of the first symptoms typically associated with a bad cold start injector is a problem starting the vehicle. 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. If the cold start injector fails or has any problems, it may not be able to supply the additional fuel required in cold conditions, and as result may cause the vehicle to experience difficulty starting.
2. Decrease in MPG
A decrease in fuel efficiency is another symptom of a bad or failing or failing cold start injector. If the cold start injector leaks at the nozzle, and allows fuel into the intake this will cause an excessively rich mixture. This leak will result in a decrease in fuel efficiency, and in some cases performance and acceleration.
3. Engine performance issues
Engine performance issues are another symptom commonly associated with a bad or failing cold start injector. If a cold start injector fails or develops a large enough leak it can lead to engine performance issues. A leaky cold start injector may result in a reduction in engine performance and acceleration as a result of the disturbed air fuel ratio. In more severe cases, where a large amount of fuel is leaking into the manifold the vehicle may even experience stalling or misfires.
If your vehicle begins to display any of the symptoms above, or you suspect that your cold start injector has failed, have the vehicle diagnosed by a professional technician, such as one from YourMechanic, to determine if your car needs a cold start injector replacement.
This article originally appeared on YourMechanic.com as Symptoms of a Bad or Failing Cold Start Injector and was authored by Ed Ruelas.