True or False: IDI chambers use a pre-combustion chamber formed in the cylinder head.

The statement is true; IDI (Indirect Injection) chambers do indeed utilize a pre-combustion chamber formed within the cylinder head. This design is a key characteristic of indirect injection systems. In such systems, fuel is injected into a smaller chamber, which allows for better mixing of air and fuel before it enters the main combustion chamber. This setup promotes more efficient combustion, resulting in reduced emissions and improved fuel economy.

The presence of the pre-combustion chamber serves several functions: it allows for a more controlled combustion process, helps in starting the engine at low temperatures, and contributes to smoother engine operation. This method of fuel delivery contrasts with direct injection systems, where the fuel is sprayed directly into the main combustion chamber. Understanding the roles and functions of IDI chambers is vital for heavy-duty technicians when diagnosing and performing repairs on various engine types.