Final answer:
When an engine fails and auto ignition fails, the combustion process is disrupted, leading to issues like knocking and reduced engine performance.
Step-by-step explanation:
When an engine fails and auto ignition fails, the combustion process cannot occur as intended. In a typical internal combustion engine, fuel is ignited by a spark plug, and combustion spreads uniformly outward. However, if the ignition fails, the fuel may not burn properly, leading to issues like knocking and pinging. This can result in uneven burning and reduced engine performance.
The combustion process in an engine relies on several factors including temperature, density, and time. Ignition occurs when the reactions produce enough energy to sustain themselves even after the external energy input is cut off. If any of these factors are deficient or disrupted, the combustion process can be affected.
In the case of auto ignition failure, the fuel may not ignite at the desired time or may ignite prematurely. This can disrupt the combustion process and lead to inefficient burning of the fuel-air mixture. As a result, the engine may not generate sufficient power and could experience reduced performance or even stalling.