Common symptoms that indicate fuel injection pump problems requiring repair include difficulty or failure to start the engine, rough or noisy engine idling, lack of engine power, engine overheating, and high fuel or oil consumption. Any of these issues are sufficient to require a certified or experienced diesel engine mechanic to diagnose and repair to prevent engine damage.
The injection pump is an intermediate component of the diesel engine fuel system, which consists of the fuel storage at one end and the fuel nozzles that attach to the engine combustion chambers at the other. The pump draws diesel fuel from tanks and compresses it to a pressure of up to 30,000 pounds per square inch in some models. At this pressure, the fuel is sufficiently heated that, when entered into the combustion chamber, it ignites. This contrasts with gasoline engines, which use a low-pressure fuel injector system that requires a spark plug to ignite the fuel mixture.
Fuel injection pumps of diesel engines are generally equipped with a governor device that cuts fuel supply to the engine if the crank system surpasses a specific rotation speed. This is designed to protect the engine from damage that such situations can cause.