We used to have to start car engines by key and listen for when the engine would “catch”. How does it know now automatically?

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This is probably already revealing how old some of us are, but we remember that we had to start our cars by turning the key and waiting to hear the engine “catch”. At that point you knew the engine was ok to proceed, and if you stopped turning the key it wouldn’t die.

How does the starter today (push button) know all this, and it never seems to get it wrong? I have never heard a push button starter fail to get it right unless some other issue like dead battery, etc. (and btw, today’s engines seem to have so far fewer issues like we used to have)

In: Engineering

23 Answers

Anonymous 0 Comments

The big thing is fuel delivery. Today most vehicles with push button ignition are either multiport fuel injected (with the injection sitting right at the intake valve stem) or directly injected (injector is in the cylinder). No more need to draw an air/fuel mixture through the intake manifold or even as far away as the throttle (carbureted and throttle body injected engines). As long as the injectors are primed you are pretty much guaranteed to have successfully ignition on the first cylinder to go through the intake and compression stroke.

Modern engines are also capable of detecting misfires as they happen so it’s fairly easy for a smart starting system to only run the starter enough just to get things going while knowing when to detect when the engine is also running and not just fired on a single cylinder

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