Injectors - Open or Closed ??

[Yellow Rose]

Our fuel injectors are tiny needle valves, which are opened and closed with a solenoid (electric coil) that gets a pulse from Mother Honda’s brain. Two questions.

1 - When the key is turned off and the engine shuts down, do the injector needles fail open or fail closed with loss of power?

2 - When the key is initially turned on to start the engine, until the engine fires, are the injectors failed open or failed closed?

 

[BryanZublin]

Andy, the injectors are closed with no power applied and when the engine is not running. During engine cranking, the injectors are pulsed to inject fuel. I'm not sure what you mean by "fail open" or "fail closed".

 

[Yellow Rose]

Fo / Fc

Thanks, Bryan for your reply.

To clarify, in the industrial world, safety shutdown valves are typically operated by pneumatic actuators with an opposing spring. The can be:

Air to open = failed closed upon loss of air supply

or

Air to close = failed open upon loss of air supply

After thinking about it after my post, I realized that during cranking, the injectors must be open / pulsing for the engine to fire. Perhaps my question is more accurately re-phrased as, "If the ignition key is turned to the ON position but not turned any further so as to not crank the engine, in this position are the injectors opened or closed?"

 

[Briank]

Closed