The injector pump in your 5.9 Cummins can be primed quickly. Priming the fuel system is needed when the fuel system has been worked on or if you ran out of fuel. Fuel filters should be replaced often, which require the priming of the injection pump. Priming is the process of getting diesel fuel to the cylinders. No special equipment or tools are necessary to prime the engine.
Get into the driver’s seat of the vehicle.
Turn the key to the “On” position and listen for the mechanical pump in the fuel tank to engage. The pump will run for about 20 seconds.