What happens to fuel injection when you come off the accelerator pedal?

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I’ve heard people say that fuel injection automatically turns off when you let the car coast in gear, but if I completely let off the accelerator in first gear, the car will only slow down to 3-5mph (depending on the car) and will then stay at that speed indefinitely like a lil’ cruise control, suggesting that the car was always injecting fuel at engine idle ratio?

I understand this kind of question has been asked before, but as this element doesn’t check out, I don’t believe it has actually been completely answered.

In: Engineering

10 Answers

Anonymous 0 Comments

The car will only start injecting fuel again once the RPMs come down towards idle. Fuel injection is computer controlled, so it can take many inputs into account when deciding whether to inject fuel, and if so, how much.

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