Final answer:
When there is a problem with incorrect valve timing in an engine, it can affect the vacuum readings. Lower-than-normal vacuum readings can indicate issues with valve timing, while higher-than-normal vacuum readings can indicate other problems.
Step-by-step explanation:
When there is a problem with incorrect valve timing in an engine, it can affect the vacuum readings. Vacuum readings are used to assess the condition of an engine and diagnose any issues. If the valve timing is incorrect, it can result in lower-than-normal vacuum readings. This is because the valves are not opening and closing at the right time, leading to a decrease in the amount of air being drawn into the combustion chamber.
For example, if the intake valve closes too early or the exhaust valve opens too early, it can cause a reduction in vacuum pressure. This can lead to various symptoms such as decreased engine power, rough idle, and poor fuel efficiency.
On the other hand, if the valve timing is too advanced, it can also result in abnormal vacuum readings. In this case, the vacuum readings may be higher than normal. This can indicate issues such as a partially open exhaust valve or a leaking intake valve.