The process of preparing a fuel delivery system for operation, specifically by ensuring it is filled with fuel and free of air, is critical for engine starting and performance. It involves manually or mechanically drawing fuel from the tank into the pump and fuel lines before initiating the engine’s combustion cycle. A typical situation requiring this action might arise after replacing a fuel filter or after the system has been drained for maintenance or storage.
This preparatory step serves several key functions. Primarily, it prevents engine damage by ensuring immediate fuel availability upon startup, thus avoiding a lean-running condition that could lead to component failure. Secondly, it reduces wear and tear on the starting system, as the engine does not need to crank excessively to draw fuel. Historically, this was a more common procedure in older vehicles with mechanical fuel pumps. While modern vehicles with electronic fuel pumps often self-prime, understanding the process remains valuable for diagnosing fuel system issues and maintaining older machinery.