Service bay high pressure common rail injector performance test

A method, comprising:

• operating an engine including a fuel injection system, the fuel injection system including two or more fuel injectors operatively coupled to a common fuel rail to supply fuel thereto and a fuel accumulator in fluid communication with the rail;
• isolating the fuel accumulator and the common fuel rail from a fuel supply while operating the engine;
• selecting a first one of the injectors;
• determining a first value representative of a first rail pressure;
• after the determining of the first value, injecting fuel with the first one of the injectors;
• after the injecting of the fuel, determining a second value representative of a second rail pressure;
• resuming the supply of fuel to the fuel accumulator and the common fuel rail while operating the engine;
• re-isolating the fuel accumulator and the common fuel rail from the fuel supply;
• determining a background leakage from the fuel accumulator and the common fuel rail without injecting from the two or more fuel injectors;
• and
• establishing an amount of fuel injected by the first one of the injectors based on a difference between the first value and the second value and the background leakage.