How do you know if your 7.3 Powerstroke Injectors are bad?

The most common symptoms of a bad injector on a 7.3L Powerstroke is misfires when the engine is cold or hard starts during cold weather.  These two symptoms are the easiest to identify for the truck owner in an everyday driving situation.  Cold hard starts are typically caused by poor truck maintained without frequent oil changes.  The second cause of misfires, usually is caused by broken injector internals or scored plunger and barrels on in the interior of the injector.


This method is not the only way to tell however, sometimes injectors will show age with normal starting but lack of throttle response until the engine is to operating temperature. If you know that the glow plugs are doing what they should and the truck has extended crank when the engine is cold, but fires right up after it has been running that is a good indication that the injectors are beginning to fail. A small initial puff of smoke followed by a thin haze of blueish/white smoke if pretty common with the truck as the engine gets some age on them, but if there is an excessive amount of smoke with cranking and a large cloud followed by a rough start up and continual heavy smoke it could be another indication of bad injectors. 


 Another issue that is commonly blamed on the injectors would be a circuit fault with ne of the cylinders. Although this could be an indication of a faulty injector, the code itself does not deem the injector bad. There are multiple things that could cause a circuit fault code such as any wiring harness between the injector and the IDM, including the under valve cover harness, or the IDM itself. The only way to know for sure is to check resistance between all of the connectors and through the solenoid of the injector. If the resistances show right through all of the wiring to the valve cover harness you would need to remove the cover and check the resistance at the solenoid without any other wiring at play.