Diesel engines differ from the standard internal combustion engine found on most cars. A regular engine uses a spark to ignite gasoline, whereas diesel engines use compression to burn their fuel. According to the website AA1Car, diesel engines use more fuel efficiently and are also more durable for this reason. The fuel pump feeds diesel gas to the engine. When the fuel pump fails, the vehicle runs poorly or will not start at all. There are some tell tale signs that the fuel pump may be the source of your diesel engine's problems.
Turn the key and listen as the engine reacts. A working fuel pump produces a clicking sound when the key turns. Listen to the engine. If you do not hear the clicking, the solenoid on the fuel pump is bad. If you hear the click, but the engine does not start, check the fuel lines for leaks. Look under the car for spots on the ground that indicate a leak in the lines. If the lines are intact, the pump is probably bad even if you hear the click.
Start the engine. If the motor is sluggish at start, this is a sign of a clogged or worn fuel pump.
Test drive the vehicle. If, when you press the gas pedal, the vehicle appears to have trouble increasing speed or loses power, this also is a symptom of a faulty pump. At this point, the fuel pump is working, but gradually getting worse and will die soon.
