A diesel injector is one of the most precise parts on any vehicle. It opens and closes several times per combustion cycle, at pressures well over 1,500 bar, delivering fuel in amounts measured in frac...

Common-rail injectors are built to tolerances of a few thousandths of a millimeter and work at over 1,500 bar. They don't usually wear out from age. They're killed by what's in the fuel : water, dirt,...