1. Refill the Tank: This seems obvious, but it's the crucial first step. Fill the tank completely.
2. Prime the Fuel System: This is the most important part. The Cummins system needs to be purged of air that entered when the tank ran dry. There are a few ways to do this, depending on your truck's specific setup:
* Manual Priming Pump (if equipped): Many 2006 Dodge Cummins have a hand-primer bulb near the fuel filter. Repeatedly pump this bulb until fuel flows freely and you see no more air bubbles. This might take several minutes of consistent pumping.
* Electric Lift Pump (if equipped): Some trucks have an electric lift pump. You might hear it whirring when the key is turned to the "on" position (but not started). If it's not working, you might need to check its fuse or relay. If it is working, let it run for a minute or two before attempting to start the engine.
* Bleeding the Fuel Filter: After priming with a manual pump or electric lift pump, check the fuel filter housing. Some have a bleed screw that you can open to release any trapped air. Tighten it once fuel flows consistently.
3. Attempt to Start: With the fuel system primed, try starting the engine. It might crank for a few seconds before firing up, especially if a lot of air was in the system. Don't crank it for extended periods without allowing the starter to cool down.
4. If it Doesn't Start:
* Check the Lift Pump (again): Ensure the lift pump (if equipped) is functioning. A faulty lift pump is a common cause of no-start after running out of fuel.
* Check Fuel Filter: A clogged fuel filter can prevent fuel flow. Changing the fuel filter is a good idea after running out of fuel, as it may have sucked up debris.
* Check Fuel Lines: Look for any visible cracks or leaks in the fuel lines between the tank and the engine.
* Check for Air in the System (again): If you’re still having trouble, repeat the priming steps to ensure the system is fully purged of air. Pay close attention to the fuel filter and any bleed screws.
* Glow Plugs (cold weather): If the weather is cold, ensure your glow plugs are functioning correctly. A glow plug issue can be particularly problematic in a diesel engine, even with plenty of fuel.
Important Considerations:
* Battery: Running the starter motor for extended periods can drain your battery. Jump starting might be necessary.
* Professional Help: If you've tried all these steps and the engine still won't start, it's best to call a qualified mechanic or towing service. There could be more serious underlying issues.
Remember safety first: Diesel fuel is flammable. Avoid working near open flames or sparks when dealing with fuel lines and the fuel system.
