However, if you're having starting problems, you might need to address potential issues related to fuel supply and/or the injection pump's ability to draw fuel. Here are some things to check:
* Fuel Level: Ensure the fuel tank has sufficient fuel. Low fuel levels can cause problems.
* Fuel Filter: A clogged fuel filter is a very common cause of starting issues. Replace it if it's dirty or restricted.
* Lift Pump: The lift pump, located on the fuel tank or near the injection pump, is crucial. You can listen for it to hum when the key is turned to the "on" position (but not cranking). If it's quiet or weak, it may be failing. You can also test its output directly (requires disconnecting lines and measuring flow rate - be careful with diesel fuel).
* Injection Pump: The injection pump itself can become air-locked. This is less likely, but it might require bleeding the system (a process involving loosening certain lines, carefully to avoid spraying diesel, then tightening). The process for this varies depending on the specific engine and injection pump. There are many videos on this online for the 6.9L and 7.3L IDI engines, but be cautious when working with diesel fuel.
* Fuel Lines: Check for cracks, leaks, or kinks in the fuel lines from the tank to the injection pump.
Instead of "priming," focus on troubleshooting these areas. If you've confirmed adequate fuel, a functioning lift pump, and clean fuel lines and filter, but the engine still won't start, then you might have a problem with the injection pump itself (or other fuel delivery components). At this point, professional help from a mechanic experienced with diesel engines is often necessary.
