Hagrid's bus engine failed. What happened?

Starter damaged, ignition coil damaged, battery dead, spark plug damaged, oil circuit problem. According to the analysis, the gas supply and ignition are normal, so the fault may be incorrect ignition timing or throttle failure. Connect the ignition timing gun and try to start the engine. The ignition timing gun shows that the ignition advance angle is 17, which is normal; Using the throttle test function of the fault detector to test, it shows that the throttle is normal. Remove the intake pipe and observe whether the throttle valve can be opened and closed normally.