Troubleshooting Hunting and Surging Idle Issues

What can cause hunting and surging at true idle?

A. A fuel delivery problem

B. Air leaks

C. Both A and B

Answer:

Both A and B

Idle hunting and surging can be caused by a fuel delivery problem or air leaks. When there is a fuel delivery problem, such as a clogged fuel injector or a failing fuel pressure regulator, the engine's idle speed can become erratic. Similarly, air leaks in the intake system, such as a cracked intake manifold or a malfunctioning idle air control valve, can also result in a hunting and surging idle.

For example, if there is a clogged fuel injector, it may not supply enough fuel to maintain a steady idle, causing the engine speed to fluctuate. On the other hand, if there is an air leak in the intake system, it can introduce additional air into the combustion chamber, leading to an inconsistent idle speed. Therefore, the statement that hunting and surging at true idle is caused by a fuel delivery problem or air leaks is true.