How to Prime a Cummins 5.9 Injector Pumpby Jared Curtis
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.
Turn the key enough to engage the starter. Do not attempt the start the vehicle. This will engage the fuel pump for about 20 seconds.
Repeat Step 3 four to five times to allow the fuel line to pressurize.
Attempt to start the engine. Depress the fuel pedal while turning the key until the engine starts.