Will a broken camshaft magnet keep the engine from firing?

A broken camshaft magnet will likely not directly prevent the engine from firing. The camshaft magnet's primary function is to provide a signal for the crankshaft position sensor (CKP sensor) or camshaft position sensor (CMP sensor), which are used for engine timing and fuel injection control. A broken magnet might prevent these sensors from getting a reliable signal, but the engine might still fire erratically or not at all, depending on how the system is designed to handle signal faults. Some systems will default to a limp mode, some may throw a code and shut down, while others might run but very poorly.

The engine's ability to fire depends on many factors beyond just the camshaft position sensor signal:

* Crankshaft Position Sensor: This is crucial and independent of the camshaft sensor. A faulty CKP sensor will absolutely prevent the engine from firing.

* Fuel System: A problem with the fuel pump, injectors, or fuel pressure will prevent firing.

* Spark System: Issues with the ignition coils, spark plugs, or wiring will prevent firing.

* ECU (Engine Control Unit): A faulty ECU can prevent firing.

In short, while a broken camshaft magnet is a problem, it's not a guaranteed cause of a no-start condition. It's more likely to cause poor running, misfires, or the engine going into limp mode, rather than a complete inability to fire. A diagnostic scan is needed to pinpoint the root cause.