Diesel engines don’t have sparkplugs. Instead, cylinders fire when a fine mist of fuel sprays into air superheated by a piston’s compression. Controlling precisely how and when that fuel sprays is the key to increased horsepower and fuel efficiency seen in recent engines. MAN’s 12-cylinder marine diesel, for example, once produced 1,200 horsepower. Electronic controls increased that to 1,300 horsepower in 1998. There it remained until common-rail injection bumped it to 1,360 in 2006. That same basic block produces up to 1,550 horsepower today (www.man-mec.com).
Even on an older diesel, that moment of fuel injection defines how well the engine runs, how much fuel it burns, and how clean the exhaust is. The flipside is that problems in the fuel system cause many diesel engine failures, including problems with components outside the fuel system. With so much riding on each tiny burst of atomized fuel, attention to a diesel’s fuel system will help keep it running like a Swiss watch. Click to continue reading this article.