The cold start injector is also known as the cold start valve, and is an important part of keeping your engine running smoothly. The cold start injector is a fuel injector that is electronically controlled and is added to the cold air intake, which is located on the intake manifold. If engine temperature reaches below a certain point, the computer lets the injector know to add more fuel into the air mixture. This helps to enrich the mixture in the cylinders, and allows the vehicle to have an easier start.

Over time, the cold start injector can become worn and not working properly due to being used every time the vehicle starts up. When this happens, the engine will have trouble idling and will sound rough. Furthermore, the engine may stall every time the vehicle is started until it warms up.

One thing that can create problems with the cold start injector is the thermometer start interval. If this interval has been set for too long, the car will crank for a long period of time before starting. The thermometer start interval will need to be reduced when this happens. The cold start injector can become clogged by debris. When this happens, the vehicle will not start at all until the clog has been cleared. If the cold start injector’s pressure is too high, your engine will receive a lean air-to-fuel mixture. This will cause the engine to start and then stop. The opposite can happen as well. If the cold start injector’s pressure is too low, a rich air to fuel mixture will happen and cause the engine to smoke, then stop, when you try to start the car. This is a serious issue and cannot be left unattended, that’s why a mechanic should be contacted immediately to diagnose and/or replace the problematic part.

Since the cold start injector can go bad over time, you should be aware of the symptoms that it gives off before it needs to be replaced.

Signs the cold start injector needs to be replaced include:

  • The engine will not run when you take your foot off the gas pedal
  • The engine will not start or it stalls while you are trying to start it
  • The engine floods when you try to start it
  • The vehicle will not start at all

If you are experiencing any of the above symptoms, you should have a certified mechanic visit you to have your problem fixed.

This article originally appeared on YourMechanic.com as How Long Does a Cold Start Injector Last? and was authored by Valerie Johnston.


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